BMW's 6-Series line launches for 2004 as a 4-seat coupe and convertible. Both use a 325-hp V8 with a choice of three 6-speed transmissions: an automatic, a conventional manual, and BMW's sequential manual. The SMT is a clutchless manual operated via console lever or steering-wheel paddles; it can be set to shift like an automatic. ABS and antiskid/traction control are standard, as is BMW's Active Roll Stabilization to counteract body lean. Options include BMW's Dynamic Drive Control that firms suspension, quickens throttle response, and adjusts shift points on the automatic transmission and SMT. BMW's Active Steering option varies steering ratio and assist. Front torso side airbags and front knee airbags are standard; the coupe adds front head-protecting tubular side airbags. Unlike most luxury rivals that use a power-retractable hardtop, the convertible has a power soft top. Its heated glass rear window lowers for roof-up ventilation or raises to deflect top-down cabin drafts. Standard equipment includes leather, wood, and metal interior trim; navigation system; steering-linked headlights; and BMW's iDrive that uses a console "joystick" to adjust major climate, audio, and navigation functions. Options include 19-inch wheels vs. standard 18s, and a head-up instrument display.