Warning about the power supply and the HP(also Dell) setup.... you will not have a properly functioning machine if you play to just run the 19volts from the Carnetix to a hacked up adapter plug... I guarantee it! (check my worklog)
you will NEED to have an auto/air adapter inline unless you're able to strip the ID chip from the adapter to give the signal over that centre pin.
As for power your DVD drive will definitely need to have a solid 5v power from either the system or a powered hub. So far I'm running my GPS and OBDII off a 4port hub(non powered at the moment) without issues.