Forgive me if this has been covered, a quick forum search didn't result in what I want. I am looking at a 2014 gas cargo to buy. Are there any known issues with the display (and some other features) of the radio/camera display system on PM's? During a second test drive the display went black. It worked and then it didn't. Also, the radio station could not be changed but the volume knob worked and the on/off button worked. No other buttons worked (media, compass etc.). The carfax report showed that the van went in to have the "sound system checked" a couple years ago, very early in the van's life (less than 6000 miles). Seems very suspicious that the previous owner had a new van's sound system checked and now I see evidence that something is wrong with it. Any insight or advice would be appreciated.