There's a few things I need to happen.
1) Turn off the seatbelt warning light in the dash. I always wear my seatbelt and I resent being told it's not on.
2) Make the buzzing noise stop. This is getting really annoying, nearly every time you put in the key it goes off. And sometimes you can be driving down the road and the thing will just start buzzing.
3) Allow the car to start every time, I guess that's the "big" one.
All of these could be fixed with a known good relay I think. If I could locate one. If not though, I'm not opposed to straight wiring some of the connections. I've removed the original shoulder-only belts anyways and replaced them with traditional three point belts. I doubt anyone would be interested in returning the car to stock so much that they'd want the original passive safety restraints and interlock relay in place.
So I'd need a schematic of the relay pinouts in order to know what to jumper to bypass it and fix all three issues above. I'll start searching for one tomorrow.
I don't have a manual, but I do have a Popular Mechanics book on the Rabbit from the 80s. It does have a section on the seatbelt interlock system, so I looked it up. The last line: "Have it checked out by a professional mechanic. It is illegal to bypass the interlock system."