Currently using a Linux PC in the dash, known as a Riocar or Empeg. It's got a 20gb hard drive with all of my digital music collection behind a great user interface.
I've got a 10" Kicker in the passenger floorboard in a custom box behind a footshield. Polk 6" mids in the doors. Rockford Fosgate 300x2 amp in the trunk. Sounds great, even over a Borla 3" exhaust and RandomTech hiflows, though other Viper owners have teased me, "If you're listenin' to the radio, you're not drivin' fast enough".
I was about to mount a micro-pc under the passenger seat so I can gain GPS navigation, a browser with bluetooth and WiFi for weather and traffic data, realtime display of OBDII data, and perhaps even accelerometer data for the track, but I'm not fond of how much space a 7" touchscreen takes up with a permanent dash mount, and none of the motorized DIN touchscreens are to my liking just yet.
-Nick Diaz
Red '02 RT/10