I have seen spring loaded roof racks strong enough for tandems. The rack pulls down to the side of your car where you secure the bike to the frame. the tensioned springs provide most of the force to lift the bike up to a flat position on the roof. The is a shop in Orange County, CA that specializes in all sorts of roof racks. They may have one. Ask in the SoCal forun.
Last edited by ken cummings; 11-05-07 at 10:14 PM.
Reason: grammer