I just setup a TX1200 as my carputer. I used a carnetix 2140 and interfaced it to the HP quickdock. The quickdock is the way to go, about $80 on ebay. Works real well, just one connector and the laptop is free. It has 6 USB ports, VGA, power, etc. etc. I am not using hte HP's screen though, but a seperate 8" touchscreen.

Radio Shack has the connector for the HP laptop power, fits perfectly. I don't remember the size right now, have it written down somewhere though. Also, if you are skilled, you can interface the carnetix ACPI leads to the on/off button on the quick dock to auto power up. Works fantastic, never misses a beat and the Carputer is always up and running, live nav and music in less than 10 seconds after ignition using RoadRunner as the frontend and IG3. I'm using a Globalsat MR-350 USB GPS, and even with the funky serial to USB adapter it always connects and resumes from standby hibernate with no problems.

Let me know if I can help. I didn't take pics of the quick-dock connection, but it's not hard once you figure out how the thing comes apart. If there is interest, I'll post instructions here. PM me, as I'm not on here much this week. Working long hours.

The only hurdle with the PC so far is living with Vista. Everything runs pretty much ok, and RR runs perfectly in Vista, except for the audio mixer. Going to have to work through that one.