Removed passenger seat to begin install of seat belts before taking car to upholstery shop. This shows the 5/16" bolts coming from the bottom with one nut to lock bolt to body so can remove seats without having to go under the car. A second nut is added after the seat frame is added. Since we were going to seat belts, I wanted to upgrade the rear bolts to 7/16" which would be much stronger. The alignment of the seat frame with the retaining bolts was a bit off, too, so plan is to fix that as well. Drilling the holes out to 7/16" went pretty quick and then I used a rat tail file to help relocate the bolts a little further outboard on each side. All went pretty well with my bolt stash giving me plenty of options. A little duct tape was substituted for a second set of hands in order to hold that inboard bolt until I could add a nut to the top side. That Backyard Buddy is great... and gets better every day as I grow older! Old Murphy must have been watching as my newly reconfigured mounting bolts were still off... not as much; but still a bit off. Opportunities! I'll go back at it tomorrow... maybe.