 Purchased this car used as a fun car/daily driver on nice days.  The performance is incredible.  I find that the engine is a little different than older BMW inline-6 in that you have to rev it for power.  The exterior has a love it or hate it design but it must be seen in person to render a final opinion.  The additional touches that the M car adds to the Z4 (front & rear valence, bigger wheels, quad- exhausts) go a long way to add some aggression to the design.  The interior is very comfortable but I have a slim build.  Interior design is top notch  with the optional carbon leather trim.  Bottom line, this is a pure driver's car, those looking for a plush riding luxury car need not apply.