I'm using the Schroth Rally 3 harness. I've used this harness in several street/track cars, so I'm very familiar with it. I mounted the lap belts to the stock seat mount points, inserting the harness tab under the seat track from the outside. The harness shoulder belts converge into a single belt that you attach to the driver side C-pillar. I installed mine under the stock shoulder belt feed-through support.