These are the pictures from many months ago... when I put the Regent's in two of our older BMW's. I was going to need to drive one of them temporarily so I thought I'd try them in them both.
This is a 1987 528. It is the slightly large one of the two cars.
I used the long belt path with the recline bar. They installed well. Both of these vehicles would still need tether anchors to actually use the seats in them.
Then the 1988 325. Slightly smaller but not by much.