The BMW is a serious driving tool that can also double as a relaxed boulevard cruiser thanks to its myriad engine, chassis and gearbox settings, for which you can save your favourite set-up for fast driving. Then, next time you find that deserted road that looks in need of some tyre marks or that twisty mountain pass, just press the M button and your BMW is instantly transformed into the sharp driving tool you expect from the M division.

Dynamic tricks

The M3 has many dynamic tricks up its sleeve like the variable M differential lock that finds you the best power balance between the rear wheels when you’re pelting it around corners. We have taken the tin-top versions of each of these cars around Kyalami and the M3 is still the champion.

Being someone who generally despises automatic gearboxes, I was also quite smitten by the DCT sequential ‘box. In concept it’s very much like the DSG trannie that VW pioneered, with two clutches to ensure that your next gear change is already pre-selected, and the changes just seem to strike the right balance between feeling it and not feeling it. Strike the paddles mounted on the steering wheel, and this ‘box changes cogs in a split second, but you still feel it changing gear – like you should in any real driving machine. Yet it’s not jerky or annoying, it gives you the mild thunk you want, and when you kick down a few cogs, it’s not shy of pushing the engine into its redline – you still get that nice throttle blip as you would in a manual.

It felt a little different sinking into the Mercedes CLK. It’s a different kettle of fish and designed for another target market – the fat cat who likes to have the fastest car on the block and doesn’t care too much about handling finesse. Yes the CLK 63 is quickest in a straight line, but throw some corners at it and its age becomes quite apparent, it really doesn’t display the same sharpness as the BMW – in steering, chassis poise or any of those disciplines. But if you want to go sideways in a hurry, those 630 newton metres will give you the ultimate hooligan experience. By the way, you can only have it with a 7-speed autobox, which is smooth enough but doesn’t quite do the ‘involvement’ trick like the BMW does.

The Audi, on the other hand, only offered a manual. As we’ve said, the RS 4 is in a different league altogether. It’s the quietest and most refined and throw a corner at it and it’ll be the most predictable beast, with those three diffs apportioning the power between all four wheels to keep the car as stable as an English worker in the dole queue. Push it too far and it understeers quite excessively though, so all that extra throttle work is just going to end you up in the hedges anyway.

True sports cars

In truth, all of these are true sports cars but none will rattle your bones or offend your in-laws with its ride quality, despite having suspension as stiff as a Bloemfontein railway worker’s Brandewyn. But how’s the scuttle shake, you might ask? None are terribly bad. It is quite apparent in the Merc; the Audi to a lesser extent and in the BMW to the point where you’d hardly notice it.

Their interiors will smother the front occupants in the lap of luxury and make rear passengers feel the squeeze, but if you’re looking for the sportiest feel, none beat the BMW’s ultra-supportive bucket chairs and small, fat steering wheel. They’ve all got some nice, sporty touches though, as if the performance divisions that made them splattered their egos all over the cabin. Kind of makes you feel special though…

If you’re in a little (or big) dilemma as to what fat-cat super convertible to buy, if you’re purchasing new and you’re an experienced driver, you’re not going to get any better than the BMW M3.The Merc CLK is simply priced so much higher than it’s worth, given its dynamic disadvantages and price that comes uncomfortably close to the million mark – it’s not really worth the very minor performance advantage you get. The Audi could make a good case for itself though, if you’re looking for a good second hand buy and with today’s market conditions, you’ll probably get a good deal on one.

But as far as the modern performance convertible goes, the BMW is still the new benchmark, delivering the most rewarding driving experience at a price that isn’t unreasonable.