The Z4 is a continuation of BMW modern roadster image created by the Z3. The long hood and short rear overhang give the Z4 a unique look in either coupe or roadster guise. While the base Z4 models feature a peppy 3.0-liter inline six-cylinder engine, the Z4 M uses a 3.2-liter to deliver 330 horsepower. During the first four years of ownership, BMW Z4 drivers receive a 50,000-mile warranty and $0 maintenance program in addition to an unlimited mileage roadside assistance. The BMW Z4 gets an estimated 28 mpg on the highway; the Z4 M tops out at 23 mpg.