Installation was EZPZ, I'm not sure what other people were running into but this is a Schroth Rallye3 using the supplied hardware, no weird cutting/drilling required on the Corbeau RRX and Corbeau brackets. It looks like it would work fine with the stock seats as well, though I'm not sure how the shoulder belt spacing would be. The tail strap is bolted to the rear seatbelt receivers behind the driver's seat, which as far as I can tell is an approved mounting point. The outside lap belt is affixed using the same spot that the factory seatbelt resides (and run up through the trim), and then the inside is bolted to the same point as the receiver for the factory seatbelt.
The harness is FMVSS certified, and puts the lap belt in a far better position than the factory four door receiver with these seats, something that made me a little nervous since day one. I'll put a passengers' side belt in at some point as well, because I like symmetry. I've retained the factory seatbelts as well because there's definitely a limitation to how thicc of a human will fit in these safely.
I will say there was definitely an order of operations here -- I had to run the harness through each of the seat holes from the back, then install the outside lap belt connection (using vise grips to keep the belt from retracting excessively). Once that was in place I disconnected the tail strap from the shoulder belts and unbolted the seat, allowing me to rotate it sideways and access the seatbelt receiver so that I could install the inside lap belt. Once those were in place I removed the rear seat cushion and fastener for the rear seatbelt receiver, bent the tailstrap bracket to ~80° near the larger hole to allow it to sit correctly, and then installed it and reinstalled the fastening hardware. From what I could find online, it seems the fasteners are all torqued to 30 ft-lbs, and to the best of my knowledge everything is secured and will hopefully never need to be tested.
Still a neat piece of kit though!
