A whole host of improvements have made America’s favourite sports car more of a thoroughbred.

It took 50 years and more than nine million Mustangs before Ford decided this icon was mature enough to making a living in right-hand-drive – it took just under four more years for the Blue Oval icon to achieve its next landmark.

The brand that put the world on wheels when Henry was steering its fortunes celebrated achieving 10 million sales of its Pony Car in some style.

On August 9 a parade of Mustangs from 1964 to the present day rolled into Dearborn, home of Ford world headquarters, then burbled out to the Flat Rock factory where the model is built.

There the cars were organised into a configuration that spelled out ‘10,000,000.’ The commas were represented by the first Mustang produced and the 10 millionth, a 2019 Wimbledon White GT V8 six-speed manual convertible.

It was an all-American day that, you’d like to think, spared a thought to the car’s biggest fanbase – which these days arguably isn’t home grown.

The Trump ‘buy American’ exhortation might well have driven this car to achieve status as the US domestic market’s top-selling sportscar status for the past three years, yet overall the car is losing ground on home turf. Getting it past that 10m goalpost required outside help; those responsible for keeping this American great are, in fact, foreigners who had been waiting decades to get one.

More than 140 countries can now access Mustang, more than half wanting it in right-hand-drive.

Though the fervour that greeted the current – and first to be engineered for right-hook – car has somewhat eased since it launched in 2015, demand for the car outside the US presently runs at double the speed that Dearborn ever anticipated.

That one in four Mustangs built last year went to an owner in China, England and Germany and that Australia is the largest export market for the Pony car, and the largest right-hand drive market in the world, suggests Ford should have tapped into sharing with the whole world a long time ago.

Still, even if it has left piles of money on the table over the decades, Ford at least is making on the deal now. Analysts say foreign buyers are a hugely profitable piece of business simply because Mustangs headed overseas tend to be decked out in the most lavish trim.

The local market GT coupe and convertible stay true to that strategy, these New Zealand market flagships - until the Bullitt coupe arrives - being better equipped than US showroom equivalents.

Of course, it could be counter-argued that you get what you pay for, too. Though the update Mustang maintains comfortably as the cheapest eight-cylinder performance coupe here, at $79,990 and $84,990 respectively the tin-topped and openable evaluation models would, if bought in America, be considerably cheaper.

But, okay, horses for different courses. US market size explains their shockingly low stickers and, of course, domestic product isn’t impacted by shipping and setting up for overseas adventure.

Retooling the assembly lines isn’t cheap and, beyond that, some markets’ countries safety, emissions and engineering regulations (from how headlights are configured to the height of a bonnet) can be troublesome. If, beyond that, the distributor feels it has every right to cut itself a handsome slice of profit pie … well, who can blame them: You’re buying something more than a car, right? Mustang is an experience, a lifestyle.

The one impression that carries through when driving Mustang is that, even with a generation of this car that is way better engineered for our tastes than any previously – not just in respect to its road manners but also in the little things, like switching the wiper and indicator wands to ‘our’ side - driving it is still very much an immersion into a different culture. Maybe even a different time.

Mustang’s standing as a quintessential American car probably lets it get away with stuff that you’d normally not find appealing, that’s for sure.

For instance, while it’s huge on design, the designers have taken cheeky shortcuts, the most commented on relating to the convertible’s roof.

The appearance in recessed is untidy because there are air gaps either side of the retracted rooftop. Any other brand would address this with covers that would close over the gap. Here, Ford gives you the covers but goes cheap (they’d say cost-effective) by asking that you fit them in (and pull out again before raising the lid). The end result is fine, but it’s a fiddly, swear-worthy task getting there. Ford’s inattention to this detail is such that, when not in use, these bits have nowhere bespoke to go. Expectation seems to be that you’ll chuck them in the boot or the back seat footwell.

You’ll see so-so build quality and some second-rate plastics, used all too openly. For the millionth time, Ford, faux chrome plastic switches ARE awful. In the coupe, every time I untethered my phone – which was hooked up because the car now has Apple CarPlay (and something called Android Auto) – the entire panel holding the USB port came out, too. Jeez Louise!

But hey, end of the day, you’ll live with, and laugh off, these factors cos … well, it’s a Mustang. If ultimate cool comes with a few challenges, so be it.

One of those isn’t drivetrain choice. Logic says the four-cylinder is a better idea for running costs and for general running about. It’s a red-blooded Green choice, with heaps more oomph than you’d think and, believe or not, a decent soundtrack. And blah, blah, blah …. you’re not paying any attention, right?

With the V8, you cannot help but be fixated. Now a genuine 5.0-litres (5083cc compared to 4951cc), the gen three version of a Coyote family that Kiwis first met when it slipped into the Falcon back in 2010 delivers both more power and torque compared to the unit in the pre-facelift model, now making 339kW at 7000rpm (redline is 7400rpm) and 556Nm of torque at 4600rpm, it’s up 33kW and 26Nm, respectively.

It also alters from direct and port injection to a higher compression ratio and achieves the same bore diameter as the engine in the Shelby GT350 with a plasma coating rather than the old engine’s pressed liner.

It has more grunt, that’s for sure. The old car felt a bit slovenly, but much less so the new. There’s enough oomph to get it to 100kmh from a standing start in 4.3 seconds with the 10-speed automatic that both test units ran. Even though peak power and torque arrive quite high in the rev range, it just feels a lot more involving now. A toe flex on the throttle is enough to bring out the monster in this machine. That’s great for street cred.

This car gets into the mood with modes. Driving modes, that is. These tweak everything from throttle sensitivity to the way the transmission shifts to the steering and traction and stability controls. And then you’re able to make even more adjustments to the way it sounds.

You’ll want to try all that, particular in respect to the noise, which remedies the one big letdown of the old GT: That it didn’t really sound the part. That’s no longer the case.

Ford’s determination to give the 2018 cars a far rortier exhaust potentially kyboshes a lucrative trade with the old car, in that almost every example – save perhaps those sent out for press use – went straight from the showroom to a supplier in customs pipes. Now you can steer clear of having to do that. The new pipes are even growlier than what was available from the parts list and smarter, insofar that the exhaust is fully variable (thanks to a small baffle and electric motor to adjust it).

This allows it to have everything you ever dreamed of, from a ‘quiet mode’ that knocks the volume back considerably to ensure you don’t wake up the whole neighbourhood when leaving home early or sneaking in late at night to various loudness settings that truly announce the car’s presence.

Is there ever a time when this blustering American nature becomes a liability? Probably. But I still reckon the soundtrack is its best asset. It didn’t get a starring role in Bullitt, Need for Speed and the Fast and Furious franchise by being a wimp.

Speaking of; the best Mustang experience comes from driving it as a manual, because it’s necessarily involving; you mightn’t like the heavy clutch and having to give each shift a moment, but it’s a great way to engage with this car’s character.

In saying that, I liked the 10-speeder a lot more than I had imagined I would. That many cogs seems like four too many for a car like this, but even though it will when left in Drive quite often slip through all 10 settings by the time the speedo shows 70kmh, it’s actually never a drag. Quite the contrary; having so many gears allows the box to maintain contact with this engine’s sweetest spots. Weird, I know, but trust me on this one.

What do you have to try is engaging into Sport mode, which holds the cogs for longer, makes the shifting faster (in both directions), and, when it knocks down a gear, it auto-blips the throttle. This is the mode in which it is worth using the paddle shifts on the steering wheel, though understand that when this occurs the car give full control – it’ll hold onto a gear and bang off the redline until you change.

That’s for road use. There are two more modes, Track and Drag, that provide sharper response still. The latter is a hoot … it’ll even count you down when launching via a set of lights that show on the digital instrument display ahead of the steering wheel.

This generation’s changeover to independent rear suspension and a tighter platform was a massive enhancement; the updated editions do nothing to endanger the good work. The ride comfort and the ease with which you drive the car are huge pluses. The convertible is less rigid than the hard-top, but not the point of evidencing body shimmy.

The standard suspension has been reworked, receiving new shock absorbers and a new cross-axle joint which Ford says increases the vehicle’s lateral stiffness, there are also new stabiliser bars. That’s all good stuff, but what really makes the difference are the cost-optional MagneRide variable dampers (which were previously only available on the Shelby GT350).

That the open car had this and yet, despite have less structural integrity, conspired to feel even sportier than the coupe was powerful indictment to its value.

The sensors are measuring 1000 times every second and they seem to miss nothing; it’s impressive how it can be bump-absorbing yet also firm when it needs to be - no bodyroll or pitching under brakes yet no thumps when you hit a ripple or a hole. And yet, for all that, it doesn’t make the car feel numbed to its environment.

The steering has been altered and you can either add or remove weight but without feeling artificial.

Another update is with the tyres. Mustang now wears Michelin instead of Pirelli tyres because Ford said the latter just didn’t offer the performance it was after. Michelin produced the tyres for the Shelby and the same tyre engineer was asked to rework the GTs.

That’s a lot of change already, yet for visual identification there’s more, with everything forward of the front doors being new metal. The power dome has gone to make the Mustang appear look sleeker and more premium; the headlights are LED and bring tri-bar (shark gill) daytime running lights. Your eyes don’t deceive. The front and rear bumpers are also new, the latter with DRLs replicated as the brake lights.

The interior also gets a brush up. It’s clearly still conceived to meet a blue collar price and shows with the issues already covered. But, overall it is better than before, not least with the dashboard, now rendered from soft-touch materials. A 12.3-inch digital instrument cluster that replaces what was an analogue arrangement is excellent; so to the 8.0-inch infotainment screen below offering Sync3 as well as Apple, Android and Waze connectivity.

I like that the volume and climate control are still operated by hard dials and that the vehicle driving modes operate via one-way toggles.

The handbrake is still too far away on our right-hand drive vehicles and though the indicator and wiper stalk positioning is sorted, their location is poor in being right behind the steering wheel.

Mustang’s ongoing challenge is selling itself to families. There are four seats and, even without a roof, it’s really only designed for two people cos of the severe shortage of rear legroom. Even if you adjust the front seats all the way forward there’s stuff all. The boot isn’t huge either, with the convertible being worse off by far. Need to make space for the roof mechanism reduces capacity to 322 litres, whereas the coupe offers 408 litres. There’s no spare for the GT just an inflator kit.

The test cars had the cost-optional part-powered leather Recaro seats which, while lacking the old seat’s heating or ventilation, are superb to sit in; offering just the right support you’d expect from a brand that mainly builds chairs for race cars.

Although ANCAP only give Mustang a three-star rating; the update at least provisions active safety features that weren’t around before, including autonomous emergency braking, adaptive cruise control and lane departure warning and lane keep assist. There’s also a reversing camera and rear parking sensors, self-levelling headlights and automatic high beam.

The original concept for this story was to determine which was better: Coupe or convertible. Gotta say that, even though the first is a superior drivers’ car, when it comes to fuelling American Dream perception an open-top Stang on a sunny warmish day is right up there with as Springsteen, burgers and McQueen. Even in bright yellow.

Has this car got the goods to pull owners of the pre-update car back into the showroom? In theory, hell yes. In reality … hmmm. The Mustang stands to be such a once-in-a-lifetime kind of car that, even though it’s just not as good, the version that has been served up until now is nonetheless going to do enough to warrant being considered a keeper.

Of course, if you’ve yet to scratch that itch and still want to experience one of the world’s most characterful cars, then there’s really no excuse for not buying into the latest GT.

It’s delivering more than just the great American experience. It’s an especially memorable and rewarding sporting car.