PURELY for scientific purposes, you understand, it was important to lower the roof of the new Audi TT Roadster even before departing on the test drive. The dash showed a parky 6C, but at least it wasn't raining.

An hour later, what should be coming in the other direction but an earlier model topless TT, with its roof firmly lowered too. So there are hardy souls who spend their own money on a car and enjoy its features well short of a sizzling summer day.

Actually, this latest TT with a folding roof is hardly hair shirt rugged even on a chilly morning, especially if you pay £1,000 extra for the open-top driving package.

That includes an electrically operated wind deflector that pops up behind the seats, which have a hot air outlet at neck level, and bottom toasting elements lower down.

That is the sort of detail Audi went into while replacing the car in its range that has done most to signal the arrival of a brand that wants to slug it out with the other mass market German prestige car makers.

So the shape is all new, but like the fixed roof coupe that arrived some months ago, it is very obviously still an Audi TT.

Adding some aluminium to the car has helped keep the weight in check, despite the extra metal needed to brace the body after the roof was lost in turning coupe into cabriolet.

The roof itself is, says Audi, deliberately kept as a folding fabric soft top and not the metal panels of rivals, which take up lots of boot room and leave you with a car that doesn't really look very cabrio at all.

The TT's top folds in a racy ten seconds and at up to 31mph and leaves a boot plenty big enough for all the luggage you and your companion are going to need for that well deserved luxury hotel break.

Getting there with the roof in place will reveal an interior rather quieter than before, thanks to three layers of acoustic damping material. It results in a car whose big tyres make more noise on a typical British road than the wind produces around the top.

There are ten versions of the new TT Roadster, starting at £31,995 for a Sport model with 2.0 184 horsepower diesel engine, a popular choice in a country like the UK where the car will be chosen by lots of fortunate drivers as their company car.

There are two 2.0 litre petrol engines offered, a 310 horsepower fire breather or the 230 horsepower of the test car, both producing more performance than the diesel at the expense of poorer economy. Audi's all-wheel drive quattro system features on some models and there is an automatic gearbox option available at £1,530.

All TT Roadsters feature the superbly crafted cockpit that first delighted in the TT Coupe, still the interior to beat at anywhere near the price.

And the cars have an instrument layout that's really a high quality display screen that allows the sat nav, where fitted, to take pride of place and push the rev counter and speedometer into the corners. All very neat.

The petrol engine provides enough power to impress, the £450 optional 19-inch alloy wheels on the test car and its firmer and lowered S line suspension doing a fine job too, so long as the road is smooth. You can opt for softer settings and I'd do that in the UK, for sure.

Not that this is a car to drive to its limits; the TTS Coupe, from £38,790 is the one for that. Better by far to drop the top and soak up every stray ray of sun, winter or summer.

FAST FACTS

Audi TT Roadster 2.0 TFSI 230PS S line quattro S tronic

Price: £37,555

Mechanical: 227 bhp, 1,984cc, 4-cyl petrol engine driving all 4 wheels via 6-spd automatic gearbox

Max speed: 155 mph

0-62mph: 5.6 secs

Insurance group: 39

Combined mpg: 42.2

CO2 emissions: 154 g/km

BIK rating: 23%

Warranty: 3yrs/60,000 miles