SeaSucker has made their name in the bike industry by offering bike racks that attach to your car with only marine grade vacuum cups. While the idea might sound preposterous, they really work and have been expanding their offerings from the smallest rack available, now to the rack with the smallest foot print. This orange creation (somewhat reminiscent of their octopus mascot) is the prototype for their new convertible/sports car rack. If you have about 1×1.5′ square of roof or trunk space available, you have room to carry a bike.
Depending on the car, this may be the only choice in applications where the glass or the trunk material won’t allow strap on racks. Like the rest of their racks, each vacuum cup uses a pump to purge the air, and has an indicator if it starts to lose suction. Pricing and availability TBD.