I started installing some new audio stuff in my Prius. I started with the rear view camera. I seen a lot of posts on here, but not too many with pictures. (The stuff everyone likes lol) For the trigger, I tapped into the wire that goes into my reverse light socket. On the plug attached to the car, it is the brown wire. That turns into a red/blue wire for the plug that goes into the tail light. I attached a picture of the plugs. Now on to the rear door speakers... Starting from the back and working forward since my new H/U hasn't showed up.
From back of the HU, there is a Video in where the Red+ goes and Ground using a Female RCA From HU to the Camera: Connect Red+ to the ReverseLight Positive, RCA to the Camera RCA From Camera: Connect RedBlackStripe to Ground, The Red+ to any positive cable trunk Connector.