Despite it being called a cabriolet, the M4 is really three cars in one.
With the top up, the car mimics a regular coupe perfectly, much in the same way the Mercedes-Benz SL does. Thanks to the hardtop design, all of the windows are large and offer terrific sightlines. Not only is this almost impossible to replicate in a soft top convertible, but thanks to the lack of B pillars, sight lines might be better than in this cabriolet than in a traditional coupe.
That leads me to the second configuration of the M4: a hardtop convertible. Since there is no B pillar, dropping the front and rear windows on either side of the car produces a nice big airy opening. This allows the M4 to offer all the fresh air benefits of a convertible while maintaining a bit of protection from the beating sun.
Read the complete BMW M4 Cabriolet Review