This a common problem? The previous owner of my freebie wasn't exactly much into body maintenance, and the jackpoints are extremely rusty. I decided to just fill up the holes with that hard spray foam insulation (works quite well in areas I cant actually remove the rust from) and then waterproofed over them. Was this a good idea? If moisture cannot get to the rust, then the rust will have a harder time spreading I assume? Are rusty jackpoints common on "daily driver" category cars? Also, I fiberglassed the rust in my backseat left and right sides. Thank god the rust was just located where the welds were located. Same thing with my VW Bug, always rust at the welds. Ah well. Just curious if any of you have had these similiar rust issues.