You can use an oil can to lube you cars body parts, nuts and bolts that are exposed to rust. Squirt a little into door, rear quarter and sill drain holes in addition to trunk lid while car sits over newspaper. Wipe excess off with rag. Let sit and drip for an hour or so on paper and dispose of. Wash and wax car a week later. Use about one quart per car per year; you have a six year supply and no rust problems ever in these areas…
http://www.zealandpublishing.co.nz/freerustproof.html