Canay, was hast Du denn bisher gemacht? Auf Deiner Homepage steht, dass Du 28 Jahre alt bist - ich ebenfalls! Wohne übrigens nicht weit weg von Dir.

Back to English:

Fritz, I chose the wrong words. Of course I remember the XJ-coupes but I meant a coupe-like 4door just like the CLS - or the Alfa 156 to a certain extend, if you wanna take it into account! The XJ-coupe had the relation of roof and trunk moved further to the middle of the car, what is a traditional item to define coupes.
This doesn't work that easily on a 4door, since you need at least a fairly sufficient head room for the rear passengers.

Canary, don't get me wrong about my harsh comments - I am working in the design business also and I want to give you some productive comments. Hope it helps!
It is common that you over-emphasize the proportions on a car drawing, and I don't know if you did it on purpose - but maybe you should take it back one step and change the relation between chassis and cabin. Make the cabin a little bigger to improve this relation and also correct the passenger side headlights a bit to the left on the picture (move it to the right front wheel).

Greetings!