I recently did a Cold Air Intake that deleted my sound tube. So I ran wiring from the front fuse box through the sound tube hole and up to the windshield area to power both my radar and cam. It works perfect, powering on when I start the car and off when i turn it off. If you want the fuses I tapped, I can send you that info as well as post some pics. However, there's a simpler solution (I ordered this and am awaiting the harness with extra leads for the cam)....
http://www.gen5diy.com/Chevrolet/Cam...ector-Harness/