I need some help been looking all over the place bought an RX8 for a project car took the interior out it was a flood vehicle. Got all cleaned out and new carpet and insulation when i went to put back in the front seats the bolts were stripped had to get a tap and di to fix the holes. Out of the 7 bolts 4 are salvageable, i have been looking up and down trying to find the bolt size, does anyone have a clue on the specs. thanks

 

the bolts will be metric measure the outside diameter it will be slightly smaller than the bolt size. For example a 10mm metric bolt will usually measure around 9.8mm.
the thread pitch is a little harder to measure. most likely 1.25mm between peaks. eg M10x1.25 All the 8mm bolts are 1.25mm pitch so you can line the larger sizes up next to an 8mm you can confirm they are 1.25. I think the alternator tensioner is 8mm from memory and easy to remove.

 

Pretty sure they are 7/16 x 20

For some reason that is the standard seat belt bolt in cars...