I know all too well about rust.
I had a 95 Z26 Beretta that was my driver for 7 years through the salt & snow. I dropped a 3400 engine in it, upgraded the suspension, wheels, etc. I dont even know how much time I spent modding it.
I knew it was starting to get rusty but I was occupied with my Camaro projects. One spring the gas tank leaked through and when I got under to replace it I saw how bad the unibody was. That was when I decided to buy a rust-free Beretta and salvage what I could from the Z...and that is where the 91 "SS" came from.
Sometimes I still miss my old baby, just for the fact it was the first car I ever did serious work to. It doesn't even compare to the current Beretta, but it was a fun ride when I had it.