i have a setup as you describe, but it is wireless.
originally for motorhome use, distributed by www.winplususa.com.
tiny screen(4"?)but not bad picture mostly.
i have it manually switched.
wireless picks up some interference now and then.
got it as a $25 toy(new) on craigs list.

'94 "tracker", with some parts from suzi the psychic.
other modifications made, with more to come.
some intentional.
suzitoo should get me fishing.
kj6esv