Thanks, they are different and retractable without a shoulder strap.I know Coupeking is selling the lap belts on their web site. Not sure if it’s the same as the 2800 though.
I actually think I can make these work if I mount the retractor for the lap belt and hard attach the fixed end.When I bought my coupe, I was planning to redo my seat belts (I ended up going with a set of Schrott harnesses instead). The expected service life of the webbing material BMW used in the seat belts in our cars was 25 years, fyi.
I actually believe I can use the original mounting locations except that I doubt there is enough room for the retractor next to the rear seat. I am still analyzing it. The typical B pillar part would be removed.Those look to be a very nice solution. I am using these: https://www.schrothracing.com/item/rallye-3-asm/tuning-Harnesses. Precludes passengers in the back seat, and doesn't look as nice as the ones you are looking at, but uses factory mounting points. I concluded that these were the safest thing available at the time.