Vice grips? Duct tape? Why not big suction cups? I did find a forum where a couple guys had clamp-on luggage racks for 356/911 Porsches, however, their links to the places that carried them turned out to be duds. When I checked their posts again I see that they were made back in 2001. The one pictured looked pretty good and could support up to 70 pounds since the weight was distributed over a larger area of the engine lid. The rack was secured at the top, bottom and sides of the engine lid and the paint was protected by rubber lining of the clamps. I couldn't tell how the clamps were drawn up to secure the rack. I'll see if I can find that site again and post the picture. If anyone invents one, it can called the Clamper, "Clamp On, Clamp Off, The Clamper!