Hard Core Z4 (BusinessWeek Online via Yahoo! News)

The arrival of BMW's new Z4 Coupe has been much anticipated by driving enthusiasts. That's largely because adding a hard top to a roadster like the Z4 detracts a bit from the car's sex appeal during summer driving, but adds to the rigidity of the car's frame, which improves handling. Enthusiasts are also eager to see whether the Z4 Coupe can match Porsche's new Cayman Coupe, a hardtop based on the Porsche Boxster that has earned raves ...