The new BMW Z4 has made its world debut at the 2009 Detroit Motor Show.

Sporting the first fully-retractable hardtop roof in BMW’s history, the new Z4 is a striking car – with sleeker, cleaner lines than its predecessor.

On sale in May, the new BMW Z4’s roof will open or shut in 20 seconds while power is provided by a choice of three petrol engines.

This includes a range-topping 3-litre twin-turbocharged engine developing 306bhp, which will accelerate the convertible from 0-62mph in 5.2 seconds before hitting the 155mph electronic barrier.

The Z4 also gets BMW’s Drive Dynamic Control fitted as standard for the first time.

DDC allows the driver to specify the car’s throttle and steering, level of ride comfort, traction control response and gear change speeds for the automatic and semi-auto gearboxes.

There’s no news on cost as yet so expect pricing to be announced closer to launch. 

It’s been an exciting start to the Detroit Motor Show with debuts including two supremely powerful Jaguars and a hot new convertible concept from Volkswagen.