I have a nasty pocket of rot under my battery tray......I did a very professional job fixing it.....I sanded the rust down, killed it all.....and filled the few holes going into the cabin with silicone.....some bondo, can of spray paint and it will match that of a macco job

Seriously though, I think as long as the rust is stopped, and it hasn't compromised anything structural.....the easiest and simplest way to keep the water out of the cabin/pockets is the best solution.....smoker's idea is a good one!

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