I would like to add a backup camera to my system and obviously need access to hook up the new cables. After removing the trim I'm left with 4 tabs on the sides of the head unit (see attached picture). You can move them back but the unit won't come out. I've tried generic removal keys but no luck again. Can't seem to figure this one out. Does any one know if specific keys are needed or am I missing something real easy in getting it out?

See if you have locking tabs like #2 in this picture. With this one, you need all 4 unlocked at the same time (recommend toothpicks or something).

That was it, thanks!