How much power do the standard AC-DC power supplies in the computers require?
IIRC, there are many who have done similar things but on other forums. Guys, wasn't there a website like MP3.com or something similar that had a forum where you could discuss this in more detail with folks who focus on it? I recall they were doing things like using custom OS interfaces & modified touchscreens in custom cases/physical installs to make their car-puter easier to use.
Alternatively you may be able to get by with using a inexpensive 12vDC to 110vAC power converter. Yes I know it's pretty inefficient going from 12v DC to 110v AC back down to 5/3v DC but it may ultimately be simpler and easier to support versus using a modified power supply that if it goes bad isn't necessarily as simple to fix/replace.
I went through a similar exercise with my netbook. I spend a few days looking for a 12vDC to 19.5vDC converter with sufficient current ratings to support my netbook. Ended up being more expensive to buy than a $50 12vDC to 110vAC power converter that fits nicely under my passenger seat and can easily be replaced should it fail (one already has after ~ a year of use).
I don't mean to discourage you but do want to offer other ways to make it happen in case the modified power supply idea falls through.
Either way, I look forward to seeing the results.
HTH. <img src="/forums/images/graemlins/kewl.gif" alt="" />
I've checked the MP3car sight, and they seem to be pushing the DC-DC units (which they sell). I may end up with an inverter, but would like to avoid that extra step if I can.