I've seen some other threads about installed Navi units, so I thought I'd add my own reviews to the mix.
I recently installed a Kenwood DDX712 head unit in my '05 Tacoma. Here are a few items, with the full write up on my site.
Kenwood CCD-2000 camera
Do I cut the Red wire or the White wire! The clock is ticking!
Full write up at my site: