I recently installed a six-point harness in my E36 M3, and thought I'd dash off some basic instructions/tips in case anybody else wants to do the same.

Tools Required: 16mm socket, T47 Torx driver, Open end wrench set, flat-blade screwdriver
(I mention the 16mm socket since all 3 of my socket sets, including the snap-on one, go from 15mm to 17mm)

1. Remove the plastic cover over the bottom of the mounting point of the bar holding the bottom outside end of the lap belt (using the screwdriver it just pops off). This reveals the size 47 torx bolt; remove this bolt, insert the mounting point of the outside harness lap belt and reassemble. Easy and safe.
2. To mount the other, inside lap belt, you have numerous options (drill a hole in the floor, fabricate something to snap into the existing belt receiver, etc.) To me the easiest and safest was to mount it to the inside rear seat bolt (which is where the existing mount connects to). However, you do *not* want to remove the seat (the device that removes slack from the seatbelt mounts down there and can be a PITA to disengage). Instead, simply remove the rear two seat mounting bolts (slide the seat all the way forward) with the 16mm socket, and then tilt the seat just forward enough that you can slide the harness bracket under the seat. You can then reinsert the bolts and voila, both lap belts are now in using the same hardware as BMW usead.

Alternative 1: If you want to get fancy, replace the seat mounting bolt with an eye bolt; then you can just hook your lap belt in each time you need it, and not have to leave it in the car

Alternative 2: Buy a harness bar, a flat piece of metal with holes drilled in it, from European Autosports. This mounts under the rear two seat bolts as discussed above, and provides a mounting point for the anti-submarine straps discussed below. Costs about $35

3) Install the anti-submarine straps under the front two seat bolts, or use the harness bar discussed above

4) Install the shoulder belts by mounting the eye-bolt (my harness is the "Y" type - both belts mount to a single strap in a Y shape, which has a hook for connecting to an eye-bolt) in the channel in the trunk under the rear deck. There are already suitable holes. To install the harness, simply fold down the seats, clip it in, and you're off. For sedan drivers, you'll have to find some other way to mount the shoulder belts since your rear seat doesn't fold.

Notes/disclaimers: I believe all of the above violates both SCCA and BMW club-racing rules and is therefore suitable for drivers schools only. I have no real knowledge of what I'm doing, and this *may* not be a safe installation (although I obviously *think* it is). YMMV, etc.

Simon Kennedy
'95 M3