This A5's specification should be as good as convertibles get. After all, the engine is the smooth, torquey 3.0 TDI (we love that in every Audi) and it's attached to the twin-clutch S-Tronic ‘box (which we like just as much in every VAG product). Lazy gearbox to suit the wafting cabrio, economy of the diesel to suit your wallet. And Audi really knows how to build great soft-tops - the A4 Cabriolet was a constant best-seller.
But things don't quite add up. The chief culprit is the gearbox, which is standard fit on the 3.0 TDI. Positives first: it's a dual-clutch, so the changes up and down the 'box in full auto are silky smooth and very slick. You hardly ever notice them and the kickdown speed is much better than in a normal torque convertor auto, too.
But around town and in full auto mode, the gearbox holds onto its gears for too long, so you're sat at 2,000rpm rather than 1,500rpm. That doesn't sound significant, but it feels wrong, and the engine should drop to lower revs as much as possible to keep the noise down. That's especially true in a cabrio, when the noise is being directed straight into your earholes.
I've driven A5 Coupes with this engine and a manual gearbox and the combination is much better. Audi will offer a manual 3.0 TDI Cabriolet in the future, but uptake is expected to be so low that there's no hurry to introduce it. Best fix this one, then.