M trim. Leather Interior, Auxiliary Audio Input, Premium Sound System, Aluminum Wheels, Consumer Guide Best Buy Car, newCarTestDrive.com's review says The BMW Z4 is a sensuous sports car.. 4 Star Driver Front Crash Rating. ======KEY FEATURES INCLUDE: Leather Seats, Premium Sound System, Auxiliary Audio Input, Aluminum Wheels. MP3 Player, Remote Trunk Release, Keyless Entry, Steering Wheel Audio Controls, Heated Mirrors. ======EXPERTS CONCLUDE: Consumer Guide Best Buy Car. In nearly all performance aspects, the Z4 shines. Acceleration, braking and handling are all excellent. The Z4 is in its element on lightly trafficked roads when one can push the car toward its limits and enjoy the engine's sonorous exhaust note. -Edmunds.com. 4 Star Driver Front Crash Rating. 4 Star Passenger Front Crash Rating.