Jaguar XKR-S convertible (2011-2014)

The Jaguar XKR-S Convertible is the most expensive car in the XK line-up, costing more than £100,000. It's based on the XK Dynamic R convertible, which is no slouch, but with an extra 39bhp and revised body styling, the S has even more performance and visual clout than its less powerful stablemate. It also costs the price of a decent family hatchback more than the Dynamic R, so it's definitely for committed enthusiasts only.

It's fair to say this car hasn't been designed with low running costs in mind. You can expect hefty fuel bills for a start, as you'll do well to get near the claimed economy of 23mpg if you use the car's full performance. It isn't exactly cheap to buy, either, and high road tax bills also come as standard. On the plus side, you do get lots of kit as standard, including leather upholstery, sat nav and bright xenon headlamps.

If you want a stripped-out, track-focused cabriolet, the XKR-S convertible isn't for you. Yes, it has revised steering and more power, but Jaguar's engineers have also worked hard to maintain the comfort and refinement that's always been part of the XK package.

Sharper reactions and greater precision make the XKR-S the car the XKR should always have been, while the exhaust note from its supercharged V8 engine is nothing short of sensational – you'll want to drop its hood at every opportunity to make the most of the bellowing soundtrack.

The XKR-S is firmer than the standard XKR, but ride comfort hasn't been thrown out of the window completely. At low speeds, you can feel small bumps, but at higher speeds it works effectively.

Overall, it's cosseting and the roof is impressively insulated, too. Dynamic mode opens a valve in the exhaust for an even sportier sound, but if you disengage it, you can enjoy a quiet and fuss-free drive. The interior gets the full Jaguar treatment, so you get lots of leather and plenty of kit.

You don't buy a car like this for its practicality, but the Jaguar is surprisingly user-friendly, as it has a useful 313-litre boot. This drops to 200 litres when the roof is folded.

The tiny back seats are only really suitable for small kids, but they'll hold a few soft bags and there's a wind deflector that fits behind the front seats to reduce buffeting. Given its performance and drop-top configuration, the XKR-S Convertible won't disappoint.

Jaguar has enjoyed a steady improvement over recent years and the brand was rated third overall in our Driver Power customer satsifaction survey in 2011. Better still, the XK was engineered to be a convertible from the outset. According to Jaguar, the extra 42kg in weight the convertible carries over the coupe is purely down to the roof's electric motors, rather than any additional chassis strengthening. With the hood in place, there's little in the way of scuttle shake.

This all depends on your point of view. The XKR-S Convertible costs nearly £20,000 more than the normal XKR. That's a lot of money given that the two cars share the same relaxed character. However, if you want a different prestige drop-top with this sort of performance, you'll need to spend much more, as the likes of the Aston Martin Vanquish Volante and Mercedes SLS Roadster cost significantly more.