I really appreciate all the good posts. I am going to be setting up a car pc in my new 2004 BMW and wanted some advice. I am real comfortable with computers and also car audio products. I am not so comfortable with power schematics and soldering any type of wires. This is the reason I am going wit h the Opus 150 W. I need some help understanding how the Opus works and if I wil have ny power issues. Here are my intentions....

Xenarc 7" touchscreen
250GB 7200rpm Western Digital
Shuttle nvidia2 chipset MOBO
Athlon 2500 XP (1.8ghz)
512MB PC3200 Ram (may add another stic)
USB buslink DVD/CDRW
USB 802.11b
USB keyboard and mouse
USB audigy NX 7.1 sound card

Full audio system with headunit and sub woofers (nothing TOO extreme, probably middle of the line stuff)

My only issue here is the power hook ups. I know little about running an additional battery in my car for the audio and computer equipment but curious to know if this is a good option. If running it off the battery is just as viable, I would rather not spend the extra money for an extra battery. I will not be running teh computer or audio wiith the car off all that much. Maybe once in a while to show the friends. My goal is to have the PC survive a crank, and go into hibernate when car is tunred off. If this is a problem, shutting the system down is also OK with me when the car shuts down.

What do you guys think? Am I headed in the right direction? do you see any holes in my plan? Again, appreciate any advice. I promise to post pics of my progress once my car arrives.