Whoops - I am wrong - you were (nearly) right - did another search: http://tarantino.webds.de/cgi-bin/tarantino/yabb/YaBB.cgi?board=kb;action=display;num=1082353701
How's it going fellas - I have never been on this site before but yours was the first post I looked at as I was interested in Bill's car as well. I saw the movie yesterday - the car was only visible for a couple of seconds, but I would be pretty confident in saying that it is a early 70's Maserati, probably a Merak, but maybe a Khamsin or a Bora. You weren't far off on the De Tomaso call - they took over Maser in 1975...