Just curious as I am not an expert by any means but having just installed my own rear camera a few months back... How would the PDC act like a trigger in an e53? I believe my PDC is engaged even when the car is in park, neutral, etc. I like the fact that my camera is only engaged upon shifting into reverse only... maybe I'm missing something but when you are sitting idling in park how would you access your navi screen?

fwiw - I have my trigger wire to my relay on the back-up lights and am very happy with the way everything is functioning...

Rob