My new GSL-SE is pretty decent for rust in most places. It looks to have been repainted and had the Ziebart treatments done to it probably 8 years ago from the looks of things, and that's helped. A few places like on the bottom of the front windshield, around the lip of the rear wheel wells, the inner part of the rear wheel well, etc. are pretty decent, and these plagued me on my other RX. So I got to thinking that with the some work I could get it very good for being as rust-proof as possible, at least on the visible body...

But then I started prepping the rear quarter panel. There was just a little spot that rusted right through on the outside behind the mudflap. I started digging and there was nothing but crud behind it. So I cut away a small piece of the bottom corner of the inside of the wheel well to reveal the back of the outter quarter panel...

Anyways, what I found was about 2 inches of hard, caked dirt inside the rear quater panel. I scraped and blew it out (sort of), but now I have no idea how to stop it from completely rusting out. Along the seem on the inside where the inside vertical piece meets the outside curved piece is just rusting away. I can't even get in there to treat it... I could spray tar, but that would just delay the innevitable for maybe 2 years max, and then it'll have rusted through the bottom, eating away my quarter panel.

Has anyone dealt with this before? The only other thing I can think of is to basically cut away most of the inside piece so that I could get in there, treat it, and then seal it all back up with fiber-glass or lots of undercoating. I'd appreciate suggestions...

 

Cut and weld. Rust is a cancer for a car. If you put treatment on it, and seal it off, you have about a good chance of it comming back.

The only way to fix it is to get rid of it. Have someone plasma cut it all out, and weld in some new metal. Then weather proof the hell out of it.

Oh yeah, check your tire wells from the inside of your car. Rx7's don't have any kind of rust preventative on the inside, so if moisture gets inside your car, your tire wells will begin to rust from the inside out. Just my $.02

Oh yeah... DAMN THE HUMID OHIO VALLEY!