Can also get a 60W 12v DC-DC power adapter for it too:
link
Also, they have a note about car applications:
Q) Can I use this DC-DC converter in a car?
A) Cars can be nasty enviroments. If the voltage will be in between 12-14,
things will be fine. However, cars can produce anywhere from 5-18V,
especially when using a weak battery. Again, few diodes should drop
V(in) by 1-2 volts, but please make sure you have a good battery!
Also, please read the NOTE below.
NOTE: This portion of the FAQ was written in March 2003. By May-June 2003,
we will have 9-18V inverter that will connect to your PW-60 OR PW-70. This
inverter will be able to sense ignition and shut-off/on your PC in a
safe manner. Please check our website, www.mini-box.com, soon.