If anyone is interested, I posted some pics of what the data on the touchscreen bus looks like on an osciloscope:

http://www.acura-tl.com/forums/showthread.php?t=76274

I need some help trying to identify the signaling method, so any comments would be welcome...

(sorry to duplicate the post from the electronics section, but I figured I'd have more eyeballs on it if I post here too)

Thanks,
Dave