i had one seat bolt rip out. i had to get some sheet metal and cut a few squares out that will fit over the hole in the floorboard and than drill a hole through that and directly through the bottom of the car. and now run a big ass bolt up through the bottom of the car and through the sheet metal and finally through the hole in the seat bracket and bolt it all up. i put a piece of sheetmetal underneathe the car and on top of the hole. kind of ghetto but its just as sturdy as it was before
On my old hatch I had this problem, the best way to fix it is take it to a place that does collision repair. Should be just a quick weld job and then respray of the necessary coatings, shouldn't be too expensive either.
Yep, if you are close enough, email me and I can do it. Done a bunch over the last few years. the bolt idea is a bad one. the tears will keep getting bigger until the whole works falls out.