THERE was a time when you'd no sooner shove a diesel engine in a convertible than expect to see a pinstripe suit at a rock concert.
That wasn't so long ago, even since derv-burning technology moved into a new generation.
Then Audi took the plunge, dropped its latest V6 TDI powerplant under the bonnet and haven't had cause to look back.
The A4 is the only cabrio in Britain to risk, or boast depending on which way you view it, a diesel engine in a convertible car.
Never mind the cheaper running costs, owners of soft tops don't want to be driving round in something that sounds like a farm vehicle, nor do they desire a car that feels in any way ponderous.
All fears can be discarded. For starters this is a lusty engine and one which recent revisions have given even more power.
It's a six cylinder 2.5 litre TDI unit producing 163bhp and in six-speed manual form - a Multitronic CVT transmission is also available - is capable of reaching 62mph in 9.9 seconds with top speed potential of 140mpg.
And while firing up the engine leaves you in doubt that its an oil-burner, once on the move the clatter vanishes completely. In fact were you to ask passengers whether they were in a petrol or diesel car they would be hard pushed to tell the difference.
Add average fuel consumption of just under 40mpg and the reasons for picking this model are compelling.
In truth, the Audi delivers in every aspect, not least its sexy profile and trademark fit and finish.
Open-top cars enjoy a long tradition at Audi, starting with the first cabriolet, a 4-5bhp Horch dating back to 1901.
The latest models show just how far the genre has come.
Take the hood for instance. It is electrically operated and retracts at the push of a button - a process that takes less than 30 seconds.
Nor do you need release any brackets or mess around with tonneau covers, and the linkage is barely visible when the hood's in position.
The car's shape takes its cues from both the A4 saloon and TT Coupe qauttro, while build quality is top notch.
The suspension has been both lowered and stiffened, and as a result feels sporty, while a 112% increase in body rigidity makes the car feel more dynamic and safer.
Standard kit for all A4 cabrios includes 16-inch alloys, remote central locking, electronic climate control, mutli-function steering wheel with single CD player and an automatic roll-over protection system in addition to the extensive safety features already fitted to A4 models.
It's easy though to hike up the price, with extras like leather upholstery costing £1,250, BOSE sound system £450, heated front seats £350 and 18-inch 9-spoke alloys costing £1,075.
FAST FACTS
Audi A4 Cabriolet 2.5 TDI
Price: £26,385 on the road
Mechanical: 163bhp, 2,496cc V6 direct injection turbodiesel engine driving front wheels via 6-speed manual gearbox
Max speed: 140mph
0-62mph: 9.9 secs
Combined mpg: 39.2
Insurance group: 16
CO2 emissions: 194g/km
BiK rating: 23%
Warranty: 3yrs/ 60,000 miles; 12yrs anti-rust; 3yrs paint