Report "My Porsche Cayman has a navigation problem. It stopped turning on sometimes when i turn on the car for the past week it turns on and works just fine or just shots off in the middle of a ride. Or works fine tell i turn off the car and after try to turn it on and it would not power up again. (checked the fuse box, all D row fuses are good as new). Does the unite gets its power threw the amp? or could it be the car key that is giving the wrong signal to the unite it self"