Built on a platform shared by the new Toyota Supra, the new BMW Z4 Roadster is the 6th generation BMW Z car and rival to the Audi TT and Mercedes-Benz SLC. An 8-speed automatic gearbox is the only US gearbox option (Europe gets a manual), equipped to your choice of two engines. A 2.0-liter turbo four does duty in sDrive30i trim, generating 255 horsepower and 295 lb-ft of torque, while a 3.0-liter turbo six in the Z4 M40i outputs 382 hp and 369 lb-ft; both send power to the rear wheels. The Z4 features a folding soft-top roof, a 12.3-inch digital instrument cluster, and iDrive 7.0, with adaptive M-Sport chassis, sport steering, and limited slip differential standard on the M40i and optional on the sDrive30i. Pricing has yet to be announced.