Double Din Radio / RT Turn Signal Camera Hook-up Wire? 2011 Mack CXU613

I've been pondering the possibility of buying a double din radio / DVD / CD / NAV and buying one that has two AV in-puts and a rear backup camera. I would like it to show me the right side of the truck automaticly when I turn on the right turn signal. Is there a way to do this on a 2011 Mack CXU613? I would need a constant power from the right signal hook up. What wire and where would I grab it from? Thanks

FYI, not planning on using the backup camera unless I use it for 5th wheel hook up or wireless trailer.

 

I like the latching relay Idea, sounds like I could tap that straight into a turn signal wire? There is a small LED outside signal near the middle of the door, not sure how hard it is to grab that wire but I don't really want to go into the BCM.
Glad you told me about a latching relay. I never heard of that before,

 

I think a FRM01 relay would work too, on the right setting. Check it out on youtube,