I have to disagree with you man. I've transported so many bodies in the back of a BMW coupe and i can't begin to stress how wrong you are. Any serial killers considering a mercedes just stop. A BMW coupe can fit 2 unalived persons with absolute ease.
This video is made by Ahoy (quality content). And it's a fairly short video (around 10min) with an interesting conclusion. I highly suggest you watch it.