i planning on buying navtool, just like most of the video converter that i have search it comes with a plug and play harness (thanx god). my main concern will be the 12v (i'm noob at this) i really don't want to run a cable from the battery to the nav, where can i find power for this (from the back of the Navigation harness?). also how my back up camera is going to detect that my car is on reverse (i assume connecting with the back up lights wired i'm i right?).

thanx everyone, i want to do my own installation.

 

Get an Add-A-Fuse from AutoZone or whatever local car parts joint you have. You will need the mini-fuse type. I believe it is Fuse #32 in the underdash fuse box. You will need a fuse for the NavTool and a length of wire to go back to the trunk. You will remove the trim pieces along the sills and you can fish the wire though the back seat to the trunk.
This was a bit more involved than I expected in that it was a lot of trim pieces to remove. Plan to spend a few hours on it. I installed a backup camera at the same time, so my total install was about 5 hours.