No need to apologize thank you very much for the advice!I tapped directly into the reverse signal wire at the tail light harness. The red wire you can see in the pics is the signal wire from the camera. I don’t recall which pin the reverse is, I just set the parking brake, turned the key to run w/engine off and put the car in reverse and used a test light to find the signal wire. I think it was Grn/Wht, but my memory is suspect, sorry!
You don't need to remove door panels, just the floor trim for the driver side, and the interior rear panels (which takes longer than you might think). I was able to route the wire up to the head unit by taking just the glove compartment out, but I do have small hands.I plan on doing this mod also soon. Which camera did you use? Did you have to take apart both the front drivers and passenger doors, or just one?
My 04 EX was a green/black wire near the tail light, and black for ground. There are some wiring diagrams floating around which I was able to use. What year is your E? I had some kind of connector that wasn't plugged into anything which turned out to be the easiest wire to access. Happy to answer more questions if you have them. Took me all day to install, but I had no prior experience.What did you tap into to get the camera to turn on when you put it into reverse?