Thanks to all those who sent replies about treating rust. Even though my Imperial is a 100% California car, sitting out in an open field for several years with leaves and mud sitting in the Flightsweep deck lid has got to take it's toll. I don't think the problem is serious, but does require attention, since I can see rust around the area of the bolts which hold on the center hub. A previous owner has also siliconed all the nuts, probably to prevent water leakage into the trunk. Bill '59 Crown