I agree with George. All of these treatments are great except in tight areas like these where a skin wraps around a frame (as with hoods, decklids and doors). Any rust that is left in those tight bends (and it is unlikely that you will be able to get it all out) will come back. You are going to have to cut, fabricate and weld. I cut off the entire bottom 2" of my decklid years ago and fabricated all new parts and welded them in. Years later - no rust. Sorry to be a buzz kill, but that's how rust is. If you lived near me, I'd help you.