Momo 4-Point Harnesses:
These mount to the aluminum seat mounts I had fabricated and bolted to the floor pan.

There's nothing like getting in your car, putting the shoulder straps on and clipping the waist belts together while people watch and wonder what the hell kind of car you have. Way too fun. These aren't the best belts in the world, and I'm probably going to get a 3 inch 5-point set up when I start doing more track time, but they are fine for now. A must have item with the air bag removed.