I have the same issue, i have a lilliput unmoded and the touchscreen freezes but pc is still alive. Then if you continue to touch the screen the pc locks up reeboots and then comes up with a system reebooted due to system failure message.
Sometimes i can unplug the lilli when i notice it has hung and then plug it back in and it will work but usualy always it crashes the PC!!!
2002 WRX - System Specs:
P4-ATX, 300W PS, 750 Inverter
7" Lilli, 5" Headrest On PC Svideo Out
120Gb HD, Audigy 2, Nvidia, GPS, WIFI
400WX4, 1200X1 Audio Amps - Rockford Fosgate
MB Quart 6.5 3way, MB Quart 5", Two MB Quart 12" Subs