Rick and his hood pin solution is THE solution to this universal problem. But instead of mounting the pins on the deck lid, mount them on the body. Remove the rear tail lights and you can drill a hole into the light cavity. Use clay or grease to index things, but you want the mating hole in the deck lid to be in the triangle area of the webbing. DO NOT drill all the way through to the outside. With the pins on the body, no head bumping. No unsightly pins sticking outside. Just a solid, no shift deck lid. Drill the deck lid hole just big enough for the pins. Any rubber/plastic bushing in an oversize hole will just get pounded into pieces by the shifting forces that are still there but no longer hitting the 1/4 panels. Try this link to some photos I took at the '04 Concorso Italiano.
http://pak01.pictures.aol.com/NASApp/ygp/Login?event=DirectView&shareInfo=Ehyt65ORhpOTTcqYhNYhgbXBELGeb4dzh6R4SZ%2f7gOA%3d&pageName=AlbumViewFromEmails&locale=en_USLarry