I've never posted on a forum before but I'm not finding any luck with my google searches so here goes. We went to the dealer and bought a used 2015 Rav XLE and got halfway home and started to hear a high pitched noise coming from what seemed like the dash. It sounds like either a vibration or a high pitched frequency. It seemed to happen above 70 mph and is intermittent. Tried with, and without the radio and AC and it still happened. We took it straight back to the dealer but they don't seem to know what is wrong either and I told them that I don't want the vehicle if they can't figure it out. They put me in a rental while I wait and I do want the car but not with an unknown problem from day one. Any ideas what it could be?