I have an avh-4100 with headrest monitors. When playing video it doesn't give me the option to output to rear dvd in Aux mode. When I unplug my iphone it lets me do it. Has anyone else had this problem or am I doing something wrong?

Working as designed. Owner's manual.

Hrmm... That's a really annoying flaw. I use CarPlay a lot for Music and Navigation. I also use the SD Card as Video source for kids in the back seat. Those are the main reason for me buying the 8100nex head unit. To say that I can use one or the other, but not both simultaneously really sux.