Roadsters have a fully automatic power folding soft top, with dual-layer material, an aluminum and magnesium frame for light weight, and a heated rear window.
The Z4's proportions, with a long hood and a rearward seating position, allow for an excellent weight distribution and good dynamics for high-performance driving. The 3.0i and 3.0si models have electric power steering, while the M has a hydraulic power steering system. Coupes get a special performance-optimized suspension calibration, and all Z4s come with run-flat tires.
Inside, the Z4's interior is rather tight, as can be expected from a small two-seater, but it is appointed with luxurious upholster and trim. The dash is trimmed in either wood or brushed aluminum; 3.0i models have faux-leather upholstery inside, while the 3.0si gets "High Performance" leather upholstery in one of four color schemes. The 3.0si also adds automatic climate control, and its top, THX-certified audio system has ten speakers, seven-band digital sound processing, and two subwoofers.
M models get a number of high-performance improvements and appearance enhancements, including M Dynamic Driving Control, a system that allows the driver to change the characteristics of throttle response along with other variables. There's also a semi-dry sump lubrication system, computer-controlled variable differential lock, a heavy duty clutch, a performance-oriented version of BMW's dynamic stability control which includes dynamic brake control and cornering brake control, cross-drilled special-compound four-wheel disc brakes, and larger front and rear stabilizer bars. Inside, the M models also get Nappa leather seat trim with firmer side bolsters, automatic climate control, white-on-black gauges, a thicker steering wheel, and brushed aluminum trim.
A Premium Package brings power sport seats with memory, auto-dimming mirrors, and Bluetooth, while a Sport Package includes Dynamic Driving Control (similar to that in the M), a sportier suspension, and larger 18-inch wheels. Standalone options include a headlight cleaning system, extended leather upholstery, a navigation system, M sport seats, and heated seats.