Wow, I so wouldn't cut a hole in the sheet metal either. Best I can do for the rear window is to mount it up high behind the window (sun glare but whatever), just under the headliner. The front is easy, right up with the mirror with the wire running up above the headliner (many of these cars have light sensors that mount both there and behind a cover in the top of the dash for auto lights/dimming).
"The one listed previously" was taken as the most recent post, the recorder located at http://cgi.ebay.com/Car-Mobile-4CH-M...item5880a43af3 . At least that one appears that it may supply the 12v for the cameras, without needing regulated power to power it.