The Step1 tuned version of Z4 E89 35is series has non adjustable aftermarket dampers and lowered springs. There are some compromises as the rear subframe chassis spring sockets, can't handle very stiff springs, so the front is more stiff than the rear. The open body limits the stiffness of the springs.
The BMW Z4 Roadster represents the interplay of classical proportions and state-of-the-art technology. The BMW Z4 sDrive35is offering a higher standard of performance ensured both by the modified straight-six power unit with BMW Twin Turbo Technology and High Precision Injection, on the one hand, and by BMW's seven-speed Sport Automatic with double clutch operation and the M Sports Package including the adaptive M Suspension likewise featured as standard, on the other.
The BMW Z4 sDrive35is also comes as standard with an M Sports Package including the M Aerodynamics Package and adaptive M Suspension featuring electronically controlled dampers for even greater agility without making any concessions in terms of comfort.