I know of an anti-rust device that works very well. It places a very low electrical charge throughout the skin and chassis of the car which is supposed to stop the ionization process that allows molecular oxygen from combining with iron ions in the metal. (Hence Fe02 or rust). I've known quite a few people who have used these devices and have never had a problem with rust.
The device is expensive though, $600 if I'm not mistaken. If you want one let me know and I'll see if I can get you one.
