I just bought a car yesterday with this stereo in it.  It worked great except I couldn't find out how to turn my backup camera on.  As I'm driving home the radio starts rebooting and never clearing the message "system startup in progress, please wait."  I've read over 100 threads on how to fix it but all the links I've found don't work.  I did the firmware update with it and it did not work.  Please help me with the link to get to the test mode and delete whatever GPS file I need to, or whatever help you can.  Thank you so much.  I really have been on here looking everywhere!