What is the senser in the rear license plate holder for? on 1996 Jaguar XJ6

There are 4 wires going into the rear license plate holder going to 2 round sensora od some kind. What are they for?

Asked by for the 1996 Jaguar XJ6
1 answer
It could be a back a up distance sensor, to alert you that you may be about to hit something. Why not call a Jaguar dealership to make sure?