irratating noise in rear of 07 Maxima

[toshoba]

I have an 07 Maxima SL.Since I drove the car home from the dealer I have had an irratating noise in the rear of my car.(sounds like a muted drum sound)They have looked at the car and have been unable to find anything wrong.I finally took the service mgr.for a ride and he was able to hear the noise and thought the noise might be coming from the tires(Continental) and or combination tires/suspension.He offered nothing to correct the problem.Anyone else out there have this problem and if so how did you fix it?

[jaspfs1]

good way to test the tires is by rotating the tires, front to back - back to front and see if it changes where the noise is coming from.

[toshoba]

I had the tires rotated at 6000miles and it didn't help,but thanks .