This has been driving me nuts for years... I have a 69 Mach 1 with the fold down rear seat. Every time I fold the seat down, the back rest dislodges. There are 2 clips at the top that it hangs on. There are 2 tabs on the bottom that look like they are supposed to clip into something but I don’t see anything to clip into. I believe this is the problem. Am I missing some sort of receiving slot or something? Does anyone have a photo handy of what this is supposed to hook into?