After a lot of research, KBS, makers of Rust Seal, have come up with a system to keep the dreaded tinworm away.
The three-step Klean/Blast/Seal system is specifically designed and formulated to ensure better surface prep, exceptional adhesion and durability, with permanent rust-sealing powers to keep your VW sound as a pound for years to come. The full range of rust-prevention products can be found on the Rust Shops website.

Who: The Rust Shop
How much: Call for price
Web: www.therustshop.com