> It could be a car power/wiring issue, or a heat/ventilation issue.

I thought about that. I've checked the wiring, and at least for the harness, it's all good. I can't say for sure about the rest of the car, but I would think I'd get a battery icon if there were power/voltage problems, wouldn't I?

As far as temperature, I have the hijack kernel on there and have checked the unit's temperature when it's started to flake out and it's not anything unsual from any other time it's running.

I'm going to try the "force car mode" suggestion here at work and see if anything happens - and if that still doesn't do anything, I'm going to try replacing the kernel with the stock "consumer" rather than hijack, although I don't see how that could have any effect.