Simply AMAZING!!!! Love them.
Installation is easy, setup is easy, quality is very good. The FM modulator works great providing good sound through the car's stereo speakers. Love the idea of being able to watch two separate movies at the same time or the same movie on both units. The extra USB plug and SDCard reader are great options. Lots of setup features to suit your viewing style. Headrest posts come with a bag of adapters to fit the right size diameter of the headrest hole in your seat - this came as a pleasant surpsise to me because I did not know they were included. The color match is nearly perfect too.
The speaker volume on each unit is really low even at MAX. It may be ok while sitting in a quiet parking lot or a ferry terminal.
The RCA cable between the units does not provide good enough quality of video to the destination unit. There is a clear difference between the clarity of the picture on the screen where the video is being played, and the one it's being sent to via the RCA cable which is visually more fuzzy.
You will not be disappointed if you buys these units.