First there was the Volkswagen Passat. Then Volkswagen chopped and changed the bodywork and gave it the swoopy-droopy lines of a coupe, called it the Passat CC and marketed alongside its less sleeker-looking donor brother.

Now there’s a new CC, which is based on the current Passat. It remains a four-door coupe but has been given a new name, the gladiatorial sounding Arteon, and gone upmarket to be anointed as VW’s flagship model.

VW has thrown its entire war chest at the Arteon to ensure this car stands half a chance of success in the niche market currently dominated by the likes of the Audi A5 Sportback and the BMW 4 Series Gran Coupe. It’s a relatively handsome machine, with the elongated bodywork managing to turn the humdrum Passat into something almost glamorous.

Brushed aluminium, great-looking grooved leather seats and faultless fit and finish do the same for the interior, even if they can’t disguise the fact it’s virtually identical to the, yes, you’ve guessed it, Passat.

The Arteon will go on sale in the autumn and will be initially offered as the two cars we drove on the launch in Germany – the 2.0-litre diesel engine with 240hp and a 2.0-litre turbo petrol with 280hp. Both will have a seven-speed automatic gearbox and four-wheel drive as standard.

The coupe drives as you’d expect it to: relaxing and laid back. Apart from surprisingly lovely steering, direct and full of feel, this isn’t a particularly involving car to drive – and arguably nor should it be (if you want that, opt for the BMW).

Our test cars were fitted with VW’s Adaptive Chassis Control switchable damper settings, with a choice of Normal, Comfort (slightly too wallowy) and Sport (slightly too firm). Seemingly more a gimmick than a useful tool, we’d wager most owners will use it once out of curiosity and then park it in Normal mode, where the car seems happiest.

Even with a healthy 350Nm of torque on offer from the petrol powerplant the car never quite feels as fast as its sleek architecture would imply. Nor does it feel slow, either, its performance in keeping with the Arteon’s fuss-free manner of making progress.

Despite having a steeply rakish roofline this remains a very usable car. There’s a huge amount of space inside – it’s a very long vehicle, after all, and 100mm longer than the Passat – and the boot stretches back a long way.

It’s not that high, though; the tapered tail means this is a car good at carrying long boxes but not tall ones. You can fit three people in the back, but it’s a squeeze as the rear seats’ stylised bolstered edges push passenger bodies closer to the centre of the car. There is plenty of space for two passengers though, and enormous legroom.

So, should you buy the Arteon or go for one of the more obvious choices? Well, if it’s down to ride comfort, there’s not too much to complain about. It scores highly with rear passenger space, and boot space is easily the best-in-class. However, the problem with the Arteon is that it’s going to come with a price tag hovering around the £40,000 mark. Now, given the market forecasters will see it as nothing more than a posh VW, and even if it’s filled to the gunnels with standard kit, its depreciation will still be predicted to fall faster than the BMW or Audi, which will lead to more costly leasing deals.