Ok, so here's what I did:
1 - Strip the S3 subframes down to the bare minimum. Mark the holes for the harnesses to attach in the required positions (I have 5 point harnesses, so 2 at the rear of the car, 2 lap belts, and 1 crotch strap) This means 1 lap belt either side of the subframe, and 1 directly underneath the seat.
I used 5 harness eyelets on each seat, and 3 matching nuts (2 of the eyelets screw directly into existing holes in the rear bench)
2 - Drill pilot holes for all the holes
3 - Using the best drill bit in the entire world (step/cone cutter), drill the hole out to the required size.
4 - I drilled 1 side of the box section just big enough for the threaded part of the eyelet to pass through, and the opposite side of the box section big enough to pass the nut through. This mean I could tighten the nut inside the box section, without crushing the box section as it tightened. (On the first seat, I drilled the hole from above so I could hold the nut from above, but quickly realised this wasn't the best way. I then but a rubber grommet in each hole to tidy it up.
5 - I repeated the above process until all 3 eyelets were mounted. I cut also cut the flat section off which previously held the wiring loom
6 - I then marked the relevant positions, drilled the holes, and bolted the sliders on using the same technique as above
7 - I then bolted the side rails to the sliders
8 - Then I bolted the seats to the side rails, and clipped the harnesses onto the eyelets
9 - The seats were then placed in the sliding runners in the car, bolted in, and the plastic trim re-fitted to the runners (and the rear belts clipped into the eyelets on the rear bench
10 - All fitted
1 - Strip the S3 subframes down to the bare minimum. Mark the holes for the harnesses to attach in the required positions (I have 5 point harnesses, so 2 at the rear of the car, 2 lap belts, and 1 crotch strap) This means 1 lap belt either side of the subframe, and 1 directly underneath the seat.
I used 5 harness eyelets on each seat, and 3 matching nuts (2 of the eyelets screw directly into existing holes in the rear bench)
2 - Drill pilot holes for all the holes
3 - Using the best drill bit in the entire world (step/cone cutter), drill the hole out to the required size.
4 - I drilled 1 side of the box section just big enough for the threaded part of the eyelet to pass through, and the opposite side of the box section big enough to pass the nut through. This mean I could tighten the nut inside the box section, without crushing the box section as it tightened. (On the first seat, I drilled the hole from above so I could hold the nut from above, but quickly realised this wasn't the best way. I then but a rubber grommet in each hole to tidy it up.
5 - I repeated the above process until all 3 eyelets were mounted. I cut also cut the flat section off which previously held the wiring loom
6 - I then marked the relevant positions, drilled the holes, and bolted the sliders on using the same technique as above
7 - I then bolted the side rails to the sliders
8 - Then I bolted the seats to the side rails, and clipped the harnesses onto the eyelets
9 - The seats were then placed in the sliding runners in the car, bolted in, and the plastic trim re-fitted to the runners (and the rear belts clipped into the eyelets on the rear bench
10 - All fitted