IT doesn't take long - a few yards and a couple of potholes will do - to discover that the new Audi A5 Cabriolet is comfortably better than the car it replaces.

For, like the recently introduced A5 Coupe and four-door A5 Sportback it has now joined, this soft-top Audi aims to add more than style to the ownership experience.

High on the list of must-have changes was comfort. Or as an Audi spokesman said: "The cars now have a much more compliant ride. It was perhaps a little bit too firm, especially for UK roads."

'Hallelujah!", you might shout in reply after years of Audis that performed beautifully on (Germanically) smooth roads but went to pieces on a typically pockmarked UK surface.

Better late than never, though. This chassis rethink has transformed the car, tested here in new Cabriolet form and as good looking and nicely crafted as ever.

Better still, order your Cabriolet with a diesel engine - much the most likely power unit in a range that starts at £35,235 with a 2.0 litre petrol engine - and you'll have a car made in cruising heaven.

Even better, the diesel will be mated to a new seven-speed automatic gearbox that perfectly suits the relaxed nature of this cabriolet.

Fancy a manual change and it will have to come attached to a petrol powerplant and only be available in three of the 16 versions of A5 cabriolet available at launch and culminating in the S5 with 345 horsepower, prodigious performance potential - and auto gears.

The two petrol engines are a 2.0 litre with 190 horsepower and the 3.0 litre six-cylinder in the 155mph S5 range topper with its eight-speed auto gearbox and quattro four-wheel drive.

It will hit 62mph in 5.1 seconds and consume petrol at an average of 36.2mpg in the official test, with CO2 emissions of 177g/km. That latter figure and a list price topping £40,000 (£51,835 to be precise) means it is clobbered in the new road tax regime.

Year one sees an £800 demand with £450 asked for the following five years.

Things are a little more reasonable for the likely best selling 190 horsepower diesel; £160 for year one thanks to a 122g/km tailpipe figure, but with most A5 Cabriolets topping forty grand there is still that £450 annual hit waiting in the wings.

This latest A5 Cabriolet is a little longer (+47mm) and a fraction narrower (-8mm) than before. Stretching the distance between front and rear wheels by 14mm and designing thinner seats have improved space inside the cabin, though it remains snug for adult-sized passengers in the rear.

They won't mind the lack of stretching room in a car designed to look good with roof up or down - it retracts in 15 seconds at the prod of a switch and closes in 18 seconds, both operations possible at up to 31mph, which will stop pedestrians in their tracks if attempted in a busy town centre.

Practicality is assured by a boot that measures 380 litres with the roof up or a still reasonable 320 litres with it folded. The rear seat has a 50/50 split if you need more luggage room and the boot lid now opens with the standard remote control key or a button in the driver's door.

Weight savings of up to a modest 40 kilos (it varies by version and the lightest newcomer still tips the scales at 1,690kgs) have come from moves as varied as high strength steel for the new front seats, an aluminium brake pedal - and even using lighter carpets.

As well as adding lightness the new cabriolet also has a stiffer body, always hard to achieve when you cut the metal roof off a design. That ought to reap benefits in both ride comfort and fewer squeaks and rattles from the roof.

Or, in the case of this car, no squeaks or rattles at all. Yes, there was the mildest shimmy on bad surfaces but not enough to matter, or really even notice after the first couple of miles.

Hood down and mesh wind deflector in place, a sunny day with 9C showing on the dash brings fresh air heaven even at a 70mph motorway cruise. Drop down to 60mph and you wonder if a hood is ever required apart from when the rain arrives - the cockpit is so cosy and quiet.

There is plenty of pull when needed and you'd really not know a diesel was doing the work until you checked the trip computer to discover even used with enthusiasm the car is returning better than 40mpg.

How comfortable does that make you feel...