Ok, little off-topic, but when, if at all, is a rust-proof coat needed? I live on the west coast (san diego), and the ocean winds have a slight but present damage factor. If I were to have my car sanded, primed, and repainted, would I need to do a rustproof coat once I got it down to bare metal?

the car (91 crx si) is completely rust free, its lived its whole life in california, but I certainly wouldn't want to cause any rust should I repaint it. Any ideas? thanks