Just so no-one gets burned, I did this to a pickup bed several years ago, and they didn't mention one thing, the surface prep can take the vehicle paint off & unfortunatly the lining isn't vapor proof, ie: rust under the rhino-lining (and the rhino lining is a bitch to get off).
Also, if you look @ something that's been lined, pour some water on it and try to stand on it, it's the slickest stuff I've ever tried to stand on outside of wet ice...
I had to spray paint the corners that began to rust before I sold the truck to cover up the rust.