Hi, When I had my series 3 aero I always used to run the wheels up both speed humps so the sump went over the dip, if the traffic had to wait it had to wait! I had it for three years and the only thing that touched the ground was the front towing eye.
On full speed humps there was not a problem (apart from the towing eye) as the sump went up with the wheels.
I would not like to think I had 1 inch less ground clearance, I think that would be asking for trouble, unless it was built like a skid plate.
