I'm thinking of fitting harnesses to my 1990 E30 M3. I reckon that a bolt into the rear parcel shelf is good because the shoulder harness would run horizontally onto my shoulders. My other idea was to have a "crotch strap" betweem my thighs coming up through the seat, as it would be easy to make a hole in the existing gap where the under-knee support cushion begins. Do you guys think this is possible? Would you bolt all fixing points to the floor/chassis, or make do with attaching the harnesses to the seat belt mounts? I have standard factory fitted cloth Recaros, not Sport Evo seats. Maybe I should fit a racing seat, but I want the car to look stock. Cheers.