@swathdiver
Rear DVD it's just an options when you buy your car.
Some cars comes with rear ENT with center dash speaker and UVB (RADIO AM/FM STEREO, SEEK/SCAN, AUTO TONE, CD, CD-R MP3, DVD, NAV, CLOCK, ETR, RDS)
Others comes with U3U (RADIO AM/FM STEREO, SEEK/SCAN, DVD, CD, CLOCK ETR...