I have AVIN 4 installation questions for the AVN4411PX610-bt-mic-7TSP AVANT 4 Multimedia Navigation System for BMW 3-Series E46 / M3 I recently purchased. I realize this is a E53 forum, but AVIN customer support is poor and YouTube did not yield answers to my questions.

Background
I purchased both the front (non-wireless) and rear wireless cameras. I am seeking to install the front camera in the grill and the rear wireless camera in the license plate light assembly.

Front Camera Questions
1. Is there an "accessory wire" in the front of a 2005 BMW 330CIC that I can tap into? If, yes where is it and how do I identify it?
2. Is there a "ground wire" in the front of the vehicle to tap into? If yes, where is ti and how do I identify it?
3. Can I just ground the front camera to the vehicle body instead of tapping into a wire?

Rear Wireless Camera Question
1. How do I identify the reverse positive wire?
2. Does it make a difference which ground wire I tap into?

Thank you!