For the most part these cars do seem to hold up better than most other cars when it comes to rust. While working on both SVX's (both 92's) I have found that it is the little things that rusted small nuts and bolts that are giving me the biggest head aches. I have had countless bolts broken or stripped due to rust causing me to have to buy whole new parts or drill and retap etc. Body panels are in relatively good condition though but for some of the things that I just wanted cleaned up I have been using this stuff called Metal Rescue. I swear by it. If you can remove the part and have a bucket or dish big enough to soak the part in this stuff will remove the rust. Youtube has plenty of videos of the stuff.
http://www.youtube.com/watch?v=IERdb...eature=related
I think the part with the most rust that I have soaked was the underside of my shift selector assembly. The way this stuff works is really impressive and the fact that it isn't an acid and isn't harmful is pretty cool. As long as you can keep the part wet with metal rescue the rust will be removed. I know it doesn't help when talking about the undercarriage or preventing rust but it really is a great product.