I love my Recaro Profi XL seats, I have them floor mounted and all the way back. It is perfect for me and I love it, but I
hate fastening the two rear bolts which are hard to start especially with my tunnel side harness and seat belt receptacle pushing on the center console. I decided try and find some studs but I couldn't find any good class 10.9 or 12.9 double ended M10x1.5 studs. I could barely find any fully threaded studs either.
I was poking around and found these ARP double ended accessory studs with M10x1.5 on one end and 1.25 on the other end. These worked out great with the addition of an extra M10 3mm thick washer.
Thread chaser, an old bolt for comparison, and the studs.
Since I floor mount my seat all the way back, I used them in the back. If my seat was floor mounted more forward, they could be used in the front.
When I change my harnesses next year, or if I have take the seats out for any reason, it will be a breeze :-)
My passenger seat is on sliders so I will probably keep them that way, even though it does look a little silly with one seat being higher, but it's not too bad....
Are these studs as strong as the OEM bolts? I believe so based on my research, the ARP site has info on their studs and best I could tell from the tiny bolt head markings, the OEM bolts are class 10.9.