Yes, one is funky. I'm almost certain the top most rear seat belt bolt hole is 12mm, 1.25 pitch. I'll be attaching small oval L-track anchors there, over my DIY wall panel, and that seemed like a great height and solid anchor point. 12mm flat head bolts are too large for L-track, so I had to go with socket cap. And to get those in non-black, I went with stainless from ebay. They should be here within a month...
There are various other bolt holes. Some match with the bolts from the floor anchors, normal pitch (forgot the M#). There are others, like around the windows, that I have yet to deal with yet. Don't know if I'll need to yet for my conversion.
Steve