2010 BMW Z4 spied!

Our spies have lifted the lid on the next-generation BMW Z4 and the big news is that instead of a fabric top, the new version of this roadster follows the footsteps of its 3-Series Convertible sibling and its Mercedes-Benz SLK rival with a retractable steel top. As the pictures of this mildly disguised Z4 prototype suggest, the styling seems more muscular. Rumor has it, the new Z4 will likely offer a twin-turbo 3.0-liter straight six-cylinder powerplant! And we hear there's even the possibility that the Z4 will be available with diesel power for the first time!