Walter, When designing and installing the full size power windows for the 97? DeLorean, I ran into the same concerns. I noticed that the heavy duty replacement drives as well as the stock equipment occasionally hit the outer door skin during operation. The main reason I found for this was the difference in curves of the outer skin and the slight flexing of the shaft for the spring worm drive depending upon the friction of the window in its tracks. I decided to braze a plate to the back of the tube shaft to prevent the flexing. This also allowed me to curve the shaft to EXACTLY fit the curvature of the door skin. This gave me the room to fit in the full size windows. BOB