I read a thread recently: Does lowering the car really help FE? or sth like that and I am quite puzzled. My car has quite smooth underbelly with smooth covers provided by factory. However, a friend after lowering his W124 says it feels more aerodynamic - he doesn't feel that much drag when pushing accelerator. Unfortunatelly no mpg stats from that source...
Here is how my wheel arches look now (not my car though):
http://www.w124performance.com/image...side_front.jpg
You can notice that the metal folds inwards. I thought that by unrolling it to reach vertical surface on the side would decrease the wheel-fender space.
By the way - here is a bodykit mounted on a coupe which helps aerodynamics, but I don't know if it's just about downforce or also reducing drag. Especially the front bumper looks similar to what we can see in Calibra.
http://img218.imageshack.us/img218/9...mmeramgcd3.jpg
http://i14.photobucket.com/albums/a3...24/W124_57.jpg