The Z4 is the most radical interpretation yet of BMW's new design direction, debuted by the current 7-Series luxury car. As a replacement for the lackluster Z3, the Z4 is tougher, wider, cleverer, more upmarket and about 10 percent more expensive; once again it's made at BMW's US factory in Spartanburg, South Carolina.

As before, it's a classic, long-bonnet, short-tailed, front-engined roadster with rear-wheel drive, but unlike last time, engines are powerful six-cylinder units only, of 2.5 or 3.0 litres. There's no poverty-spec four-cylinder. Expect a convertible based on the upcoming 1-Series to fill the void at the lower-end in a couple of years.

Transmission is by five- or six-speed manual gearbox or five-speed automatic, and there's the option of six-speed SMG clutchless-manual on the 3.0-litre. The power steering is electrically, not hydraulically, assisted for the first time on a BMW, and the hood is power-folded, rather speedily, as standard.

Other novelties include run-flat tyres, a Dynamic Drive Control function (using the 'Sport' button) which firms the steering and sharpens throttle response at the push of a button, and a Dynamic Traction Control setting which lets the keenest drivers enjoy a little power oversteer without getting in a spin. Sport suspension (standard on 3.0-litre models) and wider wheels are further options.