Precaution of rust

Hello. Today I started to rework my loudspeaker installation in the doors and to defrost/throw the doors. One thing I noticed negatively: the rust prevention in the doors. The cavity sealing is already well torn down in the fold of the door sheets below (every 1 – 1.5 cm). Will be able to get cavities wax well or badly tomorrow. With my “repair/optimization” of the chassis, I already noticed slight folding corosion on the underfloor sheets. This is not dramatic and is treated by me and therefore will not have any aftereffects. With a three-year-old car this can happen – hello!! Don’t misunderstand, I love my 93, I grew up with Saab, but slowly I start to ponder. At this point a warm thanks to GM and OPEL. In Sweden you can still see some 9000 – in the best condition. Also here in Switzerland. Unfortunately I have no.. Gruss Oliver P.S.: Pictures follow at the W ochenende in the FAQ.