BMW redesigns its 2-seat sports car for 2003, renaming it and making it longer and wider but carrying over engines. Like the outgoing Z3, the Z4 is built in South Carolina, but unlike the Z3, it has no coupe companion for its convertible body style. A manual soft top with heated glass rear window is standard. So are run-flat tires, antilock 4-wheel disc brakes, and an antiskid system. A power soft top is available. Two inline 6-cyl engines return with unchanged power. The Z4 2.5i has a 2.5 liter, the Z4 3.0i has a 3.0. The 2.5i comes with a 5-speed manual transmission, the 3.0i a 6-speed manual. Both offer an optional 5-speed automatic with manual shift gate, and, added midyear, an optional Sequential Manual Gearbox. This 6-speed sequential manual transmission (SMT) has no clutch pedal, shifts via the gear lever or steering-wheel paddles, and can be set to shift like an automatic. The 2.5i comes with 16-inch wheels, the 3.0i with 17s. An optional Sport Package includes a sport suspension and increases wheel size to 17 on the 2.5i, 18 on the 3.0i. It also adds a Dynamic Driving Control console button that quickens throttle action and reduces power-steering assist. Leather upholstery is standard on the 3.0i, optional on the 2.5i. Xenon headlamps are optional on both. A removable hardtop and a wind deflector are dealer options.