Back in 2007 Vauxhall did something so unexpected that Jeremy Clarkson ate hair.

It was the launch of the two-door Astra Coupe that prompted the heroic former Top Gear presenter to indulge in a spot of trichophagia. Clarkson had pledged to gobble down some short and curlies if Vauxhall launched the coupe… which they promptly did.

Nine years later and while the arrival of a three-door Astra coupe may no longer have the power to surprise – consequently there will be no eating of hair on my part – but Vauxhall’s GTC still has concept-car looks with the power to turn heads.

Although it rides on the same Delta platform as the Astra hatchback and estate the wheelbase and track are different and, in fact, the only exterior design elements it shares with its siblings are the door handles and the roof aerial.

It still looks like an Astra, the family resemblance is strong, but its heavily sculpted lines and high set rear end provide it with its own, sporting, identity. The GTC has a squat, purposeful stance, particularly on the optional 20-inch wheels while its profile has a fluidity that lends it momentum even when the car’s stationary.

It’s a shame that the effort that’s clearly gone into creating the stunning exterior isn’t reflected inside the car. There’s little fundamentally wrong with the interior, it could just be a little more, well, exciting.

The Limited Edition version that I tested had some splashes of leather – the seat facings and steering wheel – as well as some brightwork on the doors and centre dash but while it did help raise the bar in terms of perceived quality, there’s a little too much of the standard Astra still lingering on the inside.

The plastics aren’t particularly tactile either so if you’re the kind of person who likes to caress their new car you’ll be disappointed with the unforgiving, uninspiring feel under your fingertips but it all looks and feels robust.

There are buttons too. Lots of them literally littering the centre of the dashboard beneath the sat nav screen. More, in fact, than I’d like and I’m a man who likes buttons.

Visibility out the front is good, despite the rakish windscreen but the high beltline, which reinforces the impression – and impression is all it is – that you are sitting low in the car does impact on the view out the rear three-quarters.

Perhaps one of the most impressive aspects of the GTC’s design is how practical it remains despite sacrificing two doors and wearing a sexier, skimpier outfit but, despite its sleek profile accommodation is spacious, even in the back, where you’ll find there’s ample head and leg room for even the tallest of passengers.

You’ll be able to take their luggage too, thanks to the surprisingly large boot which has a 380-litre capacity with the rear seats in place. That number rises to 1,165 litres with the rear seats folded away. If you’ve an aversion to high lips, of the loading variety, then that could be an issue as the GTC possesses one but, that aside, you’ll find the GTC can be a capable addition to the family.

Vauxhall hasn’t spent a great deal of time or effort upgrading the interior over the standard Astra and, while that may be a disappointment, it becomes less so when you drive the GTC.

It rides on a bespoke suspension set-up that does a great job of sharpening up the handling without sacrificing ride quality. The wider track helps improve lateral stability and there’s plenty of grip to exploit thanks to the effort that’s gone in to tuning the GTC for the UK’s roads.

The ride is firm – as it should be, this is a sports car after all – but it never wanders too close to the precipice, striking a nice balance between performance and comfort. The steering is fluid and linear, and it has a nice weight, but there’s a noticeable lack of feel. Still, you can turn the wheels into a corner with reasonable expectation that the GTC’s trajectory will remain true.

The 1.6-litre turbodiesel fitted to my test car produces 134bhp and 236lbft of torque. It actually suits the character of the GTC rather well. It’s quick enough from a standing start to avoid accusations of being all show and no go – particularly important when it’s wearing huge 20in alloys and VXR-style roof spoiler – and refined enough not to discourage you from working it hard.

The flip side is, of course, that you still get excellent economy – Vauxhall claims 65.7mpg for the combined cycle – if you’re a tad more careful with your right foot.

The GTC is an attractive car, of that there is no doubt. It’s a shame it doesn’t shine so brightly on the inside as it does on the out but while there are a few issues with the cabin’s ambience there can be no complaints about build quality. It’s a well put-together car.

The fact that it’s both stylish and spacious is a huge bonus. If you’re looking for practical family transport that won’t result in endless teasing by your unencumbered friends, the GTC is about as cool as it gets.

Vauxhall GTC Limited Edition 1.6CDTi

Price: £26,010

As tested: £28,290

Engine: 1.6-litre turbodiesel

Transmission: 6-speed manual

Max power: 134bhp

Max torque: 236lbft @ 2,000rpm

Max speed: 123mph

Acceleration (0-60mph): 9.5sec

Urban: 56.5mpg

Extra urban: 70.6mpg

Combined: 65.7mpg

Emissions (CO2): 115g/km

For more information visit www.vauxhall.co.uk