The BMW Z4 is a rear-wheel drive sports car by the German automaker BMW, known as the E85 in roadster form and E86 in coupe form. Production started in 2002, and thus replaced the BMW Z3. The design addresses many criticisms of the Z3; the Z4 is larger, and has a significantly stiffer chassis. Earlier model years of the Z4 have onboard manual keyless entry remote fob smart key programming available, meaning that a keyless entry remote fob smart key can be programmed using programming instructions and no special equipment, while later model years will require special equipment and not just programming instructions.