My guess it has to do with an aftermarket security system.
It looks like a "shock" sensor. The + / - adjust would be to set the sensitivity. Usually this is attached to the body, seat or solid part of the car.
When the car is moved (Tow truck etc.) or if someone broke in and sat on or put pressure on the seat it would trigger the alarm or starter disable etc.
That's what I think it is. Just my .02
What kind of alarm system do you have in the car?
It looks a bit like the connector of a Clifford alarm system which is used to program or reset your alarm security codes and such.
If it is important enough to you then trace the wire. My money is on a glass break sensor/motion sensor. My NSX came with an aftermarket alarm system and I removed it entirely and returned it to stock.