I recently got a pre owned G37 coupe. I noticed that the right reverse sensors goes off even when here is nothing behind me. I took it to my local infiniti and they told me they had been painted over and I had to contact the place where I got the car and I did but they told me the car was already like that and they can't do anything. Can anyone tell me if I can clean them or have to replace them with new ones?

 

Check this thread:
https://www.myg37.com/forums/g37-sed...bration-2.html
Turns out the sonar transponders are specific for each bumper location. Take a close look at yours to see if you have the correct sensors in the correct locations.