What are the two openings on the rear bumper?

[mmouse]

Can anyone tell me what are the two openings on the rear bumper for. They are covered by some kind of lid that came loose on one of them and I had to apply a touch of adhesive to keep it in place. They are to the side of the exhaust pipes (inwards) and line up with the parking distance sensors but I am not sure if they have anything to do with them.

[emcman]

I would saw that is the cover for the attachment points for your tow hook. Look in your back under the floor where your spare would be and you will see a hook that screws into points in the car.

[photomat]

BTW these covers break very easily! One of mine was broken when picked up the car and another one broke after a tow. Warrantee replaced though.