My first design of the overhead...instead the GPS system, I had a 2,5 inch LCD. This I used for my Rearview (camera). So you dont need a rearview mirror.
I drilled a hole under my Rear lisence plate. There I installed a Night view cam. Ofcourse there are more places where you can make it. But I wanted max rearview `performance`..lol
Now, I made a VGA switch to my 2 lcd`s in the dash. So now I can switch between:
Camera front or back
DVD / DIVX
Or games
My old 2,5 inch LCD
Hole under lisence plate for camera