In a market currently obsessed with the kind of folding metal roofs you see on Coupe Cabriolet-type models, Audi's A4 Cabriolet with its conventional fabric top makes a refreshing change. It may be in its final days on sale but it's still still our pick in the quality convertibles sector.

The reasons why have become more and more apparent in the course of the long term test to which we've been subjecting a 3.0-litre TDI diesel version of this car over the last six months. For a start, consider this: the fact that this A4 makes less of a hole in the air on the move with its roof open than BMW's rival 3 Series Convertible does with its top closed. So much for the benefits of metal roof convertible technology.

Metal roofs add weight too - which blunts performance and reduces fuel economy. That's one reason why BMW's 325d Convertible can't keep up with our A4 3.0 TDI convertible: to get comparable performance, you'd have to stump up over £3,000 more than the Audi's £34,000 asking price and go for a 330d Convertible model. But aren't there other options in the sector? Well not really. Saab's 9-3 Convertible doesn't have the Audi's cachet or its build quality and the diesel offering isn't as strong. While Mercedes' CLK Cabriolet is just too expensive.

Those are all the bland, factual reasons why we've fallen in love with our A4 Cabriolet. But they don't tell the whole story. This car is so effective at what it does that it simply spoils you for anything else. Everything about it just works.

"Everything about it just works"

Yes, of course, there are a few practical restrictions to running such a car: there always will be. Let's take the bootspace, after all. There's just 246 litres with the roof down or 315 litres with the top up: enough space for two golf bags in real terms, Audi tell me. Well I don't play golf but I do know that you can fit a medium weekly shop in there as long as it doesn't happen to take place at the local cash and carry. I also know that the child seat fits snugly in the back (though baby Amy's dirty shoes make a fearful mess of the seatback in front) and that a full complement of school bags and PE kit sacks sit comfortably in the boot.

Let's be honest though, if you've enough money to own one of these, then it won't be your only car. Which means that, like us, you'll probably have something more practical for those times when space must necessarily be a priority over style. When it isn't and you can just enjoy driving the thing, then like me, you might be surprised that the handling is a good deal sharper than you might be expecting for a car of this ilk.

That's largely down to the modifications made in 2006 to the front and rear suspension in pursuit of sharper handling and the option of the sharper Servotronic speed-sensitive steering set-up fitted to our particular long term test car.

Ours, as I said, is the top 233PS 3.0TDI quattro model but apart from that, there's a wide engine range from which to choose, at prices beginning from around the £26,500 mark. My personal favourite from the petrol line-up is the brilliant 200PS award-winning 2.0TFSI engine that slots in above the 163PS 1.8T and just below the 256PS 3.2-litre quattro. The 344PS V8 S4 variant is also under-rated and I've an enduring soft spot for the 420bhp RS4 version that's now sadly out of production.

It's always been the case with this car that unless you opt for either of the V8 models, the performance feels pretty relaxed, a legacy perhaps of the car's not insubstantial 1560kg of total weight. That's one reason why the extra torque and fuel economy of the diesel variants makes them so attractive and the main reason I chose the 3.0TDI. Another option would have been the 140PS 2.0TDI variant.

We see this car as a design icon and the main reason why is the obvious thought that Audi's engineers have expended on the beautifully-lined three-layer roof which hides beneath an aluminium-trimmed solid tonneau cover when not in use. Electrically operated of course, it opens or closes in 24 seconds and there are no fiddly manual latches to break your nails on before you can press the button. The whole thing can also be done from the outside of the car by using the remote control keyfob, something the kids never tire of getting me to do in the school carpark as we approach.

A nice option that we insisted on was Audi's beautifully engineered wind deflector (essential if you want to comfortably drive with the roof down at speed), though in use, it effectively reduces your car to a two-seater. The rear window is a proper heated glass affair, which clears quickly when I jump into the car early in the morning on the school run.

Safety-wise, there's the usual complement of front and side airbags and there twin roll bars that automatically pop up in a blink of an eye behind the rear head restraints should the car be in danger of rolling over.

Most cars feel old as they get towards the end of their model lives. This one just doesn't. Audi could continue to sell it here successfully for another two or three years - but sadly, they won't. Get one while you can.

TOP 5 A4 DEALS

The results below show the top A4 deals on buyacar

	Audi A4 1.8T 2dr Cabriolet Convertible
	ETR	Mthly £440	Saving £2,534	Price £24,006
	Audi A4 1.8T Sport 2dr Multitronic Cabriolet Convertible
	ETR	Mthly £477	Saving £2,776	Price £25,964
	Audi A4 2.0T FSI Sport 2dr Cabriolet *STOCK* Convertible
	ETR	Mthly £471	Saving £2,763	Price £25,852
	Audi A4 1.8T Sport 2dr Cabriolet Convertible
	ETR	Mthly £451	Saving £2,617	Price £24,673
	Audi A4 2.0T FSI 2dr Multitronic Cabriolet Convertible
	ETR	Mthly £487	Saving £2,840	Price £26,475

typical 11.42% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000