Roadster roars in

Should they retain the retractable cloth hood for the Roadster (which was first seen here in 2000)? Or should they follow the current crowd (see the forthcoming BMW 3 Series Convertible) and install a folding hard-top?

Ostensibly, Audi says it has persisted, against the trend, with the soft roof for aesthetic reasons but there is also a strong argument in favour of the weight and space-saving nature of the rag-top.

The luggage capacity of the extremely curvaceous TT was never massive in the first place so keeping everything compressed into its own compartment won't put it at a disadvantage as the roof now takes up even less space courtesy of its compact Z design.

Luggage capacity has risen from 180 litres in the front-wheel-drive and 220 litres in the previous quattro versions to 250 litres in both models.

You don't need a fiddly load cover to protect items in the boot from being crushed, but I do have one concern - and that is the exposed areas left when the roof is retracted.

The rigid front section of the roof doubles as the tonneau cover. But there are gaps at the side into which small items could fall and potentially foul the roof mechanism. Because there is no flip-up tonneau, the Audi roof is among the quickest around, taking a breezy 12 seconds to operate (at speeds up to 19mph).

By keeping the weight penalty down (the new Roadster roof is actually lighter than before thanks to the combination of its steel and aluminium framework), Audi retains the agile handling characteristics which have made the TT such great fun to drive.

The roof (which includes a heated glass rear window) now also comes with hands-free operation, being raised and lowered at the touch of a button via an electro-hydraulic system.

As well as being lighter than before, the roof also brings with it more sound proofing with the installation of an additional layer which makes for a quieter and more refined cabin atmosphere.

And I would advise using the powered mesh wind deflector, which is a good simple design and looks extremely classy.

The new TT Roadster is now not only a fractionally bigger car, it is also a lighter one as it becomes the first open car to use Audi's hybrid Space Frame structure.

This combines aluminium (58 per cent) and steel (42 per cent with much of it in the rear floor sections and strengthened A pillars to compensate for the loss of the roof), although there is more steel (for strength) in the Roadster than the Coupe.

As a result, Audi claims a 120 per cent improvement in static torsion rigidity, which is immediately noticeable with next to no flexing in the body over bumps.

But at the same time it isn't so stiff that it can be irritated by road deficiencies, adding up to a distinctly better road ride than before.

The TT Roadster also uses a new rear axle with a multi-link suspension layout (the front retains the MacPherson structure with triangular lower wishbones) which give it a more mature ride quality.

This is also assisted by a wider track - up 44mm at the front and 45mm at the rear.

Audi is also making its magnetic ride system an optional extra. This uses dampers filled with a fluid containing minute magnetic particles that change the viscosity of the fluid when an electrical charge is passed through them, in effect increasing resistance to damper movement.

New electromechanical speed-sensitive steering is another gain for the handling package with more assistance at slow speeds and less as the speed increases, giving the driver a better "feel" for the car.

Keeping everything in check, Audi has fitted the Roadster with an entirely new high-performance braking system where the front disc brakes generate 15 per cent more friction for improved responses, adding reassurance to the TT's other qualities.

With Audi's patented quattro system installed with the V6, some 85 per cent of the torque normally goes to the front wheel but in extreme situations it is able to transit up to 100 per cent of the power to either of the axles.

Propulsion comes from the choice of two petrol engines (as used on the Coupe), a new two-litre turbocharged FSi which boasts the best power-to-weight ratio in its class and is matched to front-wheel drive and the familiar, compact, transversely mounted 3.2-litre V6 with Audi's famed quattro four-wheel drive.

The new 200bhp four-cylinder two-litre with direct fuel injection and an exhaust-driven turbocharger feels less under pressure than the previous 1.8T and claims a rapid 6.5 seconds to reach 62mph before hitting a 147mph maximum while returning 36.2mpg on the combined cycle road run.

This gem of a unit is more than adequate for most people's needs, being responsive and fluid in all situations.

Its established bigger brother pushes out 250bhp to complete the dash in 5.9 seconds, is limited to 155mph and returns 29.7mpg.

This is an almost irresistible combination of raw power (accompanied by a nice bark from the exhaust) and docile urban driving that offers more flexibility than before, thanks to modifications to the engine mapping which have improved the throttle response and made progress more linear and less erratic.

Both engines are available with a six-speed manual or the £1,400 option of a six-speed S tronic semi-automatic transmission with sport mode (now taking over from DSG).

Because the S tronic has the option for manual selection from the gear lever or steering wheel paddles, something which it does effortlessly, this would be my choice over the slightly notchy manual, which needs forcing through at times.

Visually, like its Coupe sister, the Roadster is a refinement of the original TT, one that is more mature and grown-up with a more stretched appearance - in fact the Roadster is 137mm longer and 78mm wider than its predecessor but only 8mm higher.

Major differences are the flattening out of the designer curves that characterised the original, the fitting of the tall Audi family double-decker grille and thinner, squinting headlights.

Like the Coupe, the Roadster now also comes installed with a retractable spoiler (which raises at speeds over 75mph so should never be seen in the UK) rather than the ad hoc add-on that they were forced to fit on the previous model.

The two-litre can be identified by its twin exhaust pipes grouped together on the left side while the V6 has two individual tailpipes mounted left and right as well as the quattro insignia and a high-gloss finish front grille, chrome detailed headlamps and darkened rear light clusters.

It's much the same story inside the now more comfortable and spacious cabin where some of the shock of the original has been toned down (such as the grab handles) while a flat-bottomed leather-rimmed steering wheel adds a sporting touch.

There are still some nice sophisticated touches such as aluminium interior detailing while the dashboard is more open and flowing, giving it a nice contemporary and sophisticated feel.

Standard specification on all models includes the powered roof and wind deflector, sports seats with leather and Alcantara upholstery (2.0) or full leather (V6), electronic climate control, new generation MP3 compatible audio system with single CD player, side air bags, electric windows and Audi's Driver Information System.

The V6 versions also lay claim to heated front seats, an exterior lighting pack, quattro four-wheel drive and 18in 10-spoke alloy wheels.

Of the 8,000 TTs Audi expects UK drivers to purchase in a full year (that's more than in any other country), up to 3,000 of those will be the Roadster and it's not difficult to see why after just a few miles in its company.

Prices start at £26,915 for the Audi TT Roadster 2.0 FSi and £31,535 for the 3.2 V6.