I had issues with the parking sensors on our E55 AMG this past winter. The owners manual has instructions on how to clean them-which I did. I also made sure they were securely plugged in from the rear. So I reached up behind the bumper and did so. This took care of my problem. It is worth a try on yours. If not, from what I have read you can have the dealership scan to figure out if an individual sensor is bad. Good luck. I know the annoyance of having those sensors sound when they should not be making any noise.I can be sitting in the car going nowhere or manoeuvring with no obstacles nearby. I have given the sensors the obvious clean with no joy. Is it easy to single out each sensor without taking the car to pieces. If I tape over them I presume they will sense the tape and bleep away continuously. The ultrasonic signal thing is interesting, I don't think there is a pattern regarding where I am when the sensors kick in, but I will take a conscious note. Yeah, not a continuous issue and I turn the sensors off when it annoys me. Trouble is when you turn them off and you forget you have done so ....I've had a couple of close calls, you get used to waiting for the alarm and stupidly don't look so carefully. Any suggestions appreciated.