Never-Seez, Copper-Cote, Cop-A-Slip, or a similar metal-filled lubricant is designed to smear onto fasteners that you will want to remove again... eventually. Either the copper or aluminum-filled stuff will do, and there are many brands, all doing the same job. Suspension components and exhaust studs are probably the worst offenders in the tough-to-remove list. Once you get the rusty buggers apart, make the job easier next time with a dab of this stuff. It is also good to put a dab on wheel studs before bolting them up, it helps to torque them on properly. A little bit goes a long way, but try to keep it off of your person, it can get everywhere.