I get the ground from the handbrake bolt. Just pull the cup holder up to access to that bolt. No scrapping paint needed.
I've seen this warning a few times in the Chilton book. I think I'll play it safe and disconnect the ground.
Also, any suggestions on grounding? I know anything connected to the frame should work, but I'm curious what most people do for this.
Thanks for the reply. This is definitely encouraging and it seems like this is a doable project. I may actually buy a barebones system from mp3car.com to support the forums. It seems like a better deal than what mini-box.com was offering.