p2140. before my carnetix psu, i had a reliable auto-car adapter plugged into an extra cig lighter socket i hardwired in order to hide it behind my dash. incidently, my monitor was also powered the same way. as for starting it up, i had a pulse timer relay soldered to the power switch leads. check out the $35 auto-on laptop module by webmaster. i would have definitely got his originally but he was away when i was building my carpc. the laptop shut-control program works well to automatically shut down/hibernate when power is off.
the enemy of good is definitely better. if it ain't broke, don't fit it.