Is the diesel fuel responsible for rough starting of my mercedes?

the transmission shifts normally until the last gear and will not shift also the cluster is randomly going out with a engine dianostic light.

leaks all the time

My automatic window "ground" to a halt while it was down the other day. It sounded like the motor was still working but like some gear structure broke and was ground up. I need to know how to get the door panel off to see what the damage is. Can someone direct me to some diagrams and directions about how to do this?