Retro review: E64 BMW 645Ci Convertible

This review was first published in Issue 131 of Top Gear magazine (2004)

There is a special kind of hatred, a vicious little font of vitriol I reserve for people who buy convertible cars in the UK and then drive them with the roof up on sunny days. They make me want to shout and make obscene gestures, such is the helplessness that I feel for unrealised potential. After all, we get precious few rays in this country, it’s a shame to waste ’em.

Which leaves me in a little trap of my own making when I discover the keys to a 645Ci Convertible, a long journey ahead and changeable weather crowding the heavens. What to do? Do I chance the elements and risk any last vestige of cred as the sky lobs a thunderstorm across the A1? Or do I become the very person I hate and drive around with the roof in place?

The compromise: make the first part of the trip roof up, and the last with a more roofless attitude. It is my duty to test all aspects of the car’s performance, after all. So first we assess the car with the topping in situ, grey canvas stretched over a fair amount of the surface, quite long, quite low. It’s not as abrasive as other Beemer designs of late, but it equally ain’t no suited-and-booted Merc CLK cab. I like it.

Start-up brings a pleasantly thumping great whump from the twin exhausts – even though this engine is the same Valvetronic V8 found in the 7 Series, it sounds much meatier thanks to a less restrictive exhaust. Inside, we get treated to hatchet-slash new-Beemer architecture, as in the 5 Series. Although there’s not so much clash in the groovier confines of the 6’s cabin. Comfort in front is big; space in the back not so comforting.

That’s by the by, really. This car immediately feels the most responsive, the most animate of the big convertibles, even with the automatic gearbox tested here (a £1,350 option). The steering lacks BMW’s excellent active system, but is actually pretty fine without it. Likewise, the servo-assistance of the brakes and controls is light, but not without feel. The engine is a delight, sounding like a tamed NASCAR and not short of shove in any of the six well-spaced gearbox ratios.

Roof down is just an excuse to hear the engine a little better. So it’s not the fastest of roof mechanisms (not compared to a Z4’s lid), but it’s neatly stowed and the glass wind deflector drives up and down behind the rear seats with a nicely liquid motion.

When you drop that roof, you call into play enough amperage to make Dorset go dim. A 6 Series has enough electric motors to get a bit-part in the next Terminator movie – 112 of them. They control everything from the bootlid to the headlamp washers, the windows to the (optional) active headlights. As a result, the modern BMW (and Merc/Audi for that matter) is looking like it could be a time bomb for future users. Can you imagine trying to fix a CAN-bussed integrated system through the iDrive? Computer-like depreciation is not welcome. In 10 years, what will a 6 Convertible be worth?

I like this car though. It looks different, feels different and goes like stink. It even drives hard. With the current competition, it’s hard to beat for fitness of purpose.

Verdict: Pose with serious punch. You’ll want to drop the roof just to hear that gorgeous engine rumble.

4.4-litre V8
333bhp, RWD
0-60mph in 6.2secs, max speed 155mph
£55,900