[andyu911]

Doofdog, this is what I did to install the lap belts.
The one on the left, you could use the factory mounting point. One the right side, I drilled a hole for the eye bolt at the center tunnel behind the seat. Watch for the fuel lines. Get a backing plate for the bolt. The hole could be covered by the carpet if you decide to sell your car later. Schroth makes 4-pt. harness and is pretty popular, but I like their 5-pt. It's more expensive, but money well spend.
Andy
'87 Carrera