When I started the car up and went to backup, I noticed the rear camera did not turn on. I put the vehicle back in park and then in reverse and it was the same. I turned the car off and back on and the screen was still frozen. I noticed that the CD was playing but the volume controls and eject button would not respond. I had to hold down the power/volume for about 15 seconds to get the system to shut down then reboot. After that, everything worked normally. The unit appears to be defective and can only be replace by the dealer.