Z4 is one of the most well known roadster all the over the world.  Powered by one of the smoothest 6 cylinder engine, the sound and free revving nature make it perfect for a roadster on a nice, twisty road.  Its the appeal of this car that makes it quite special.  Cabin could be romier, but then its oriented for having fun behind the wheel.  The folding roof is hardtop which is a practical thought