I've had a Z1 in my truck for about 6 months with no major problems. I have the steering wheel remote control interface, IPOD adapter, bluetooth, and backup camera installed (I have not correctly programmed the steering wheel remote yet).
Recently, the screen has started behaving as if someone if constantly clicking it. The behavior usually begins about 5 minutes after startup (although it is not consistent). It always seems that the error is in the same portion of the screen ( roughly between the pause/ play and stop buttons while running DVD, but the behavior happens in all modes)