I'm relocating my Blaupunkt ME3 DVD Player/TV Tuner into my trunk (fitting it in th glovebox just seem like too much work after all). I would perfer not to run power, ground, and remote wires from the back of the headunit (where I have them spliced now) to the trunk, so where is the best place to tap into these connections back there? I figured I'll mount it by the CD Changer (probably in the space where the OEM nav unit would be mounted, if I had that from the factory).

Also, what is the best way to route the AV cables? Will they fit under the door trim? Or should I run them a different way?

Pics would help. Thanks in advance for the help :-)

I'm guessing it doesn't need much (less than an amp), so you could take it off the rear amp as well.
The cables will easily fit under the door trim, I've got 3 pairs of decent RCA's down one side and 4AWG power down the other.

it may be difficult to determine which ones I should tap into. If its just those, then I'll be fine. Thanks again for you help :-)

Interference is usually caused by a bad earth, either on the amp, or the HU or using cheap RCA's. From a technical point of view it is always wise to run the RCA's down the opposite side of the car from the power cable, but I've done both on many cars and never had a problem. On cars I've worked on where the dreaded buzz is present, the route of the RCA's has made no difference, it's always caused by a failure somewhere else. Reasonable quality RCA's well earthed at each end provide all the interference protection you should need. Rerouting RCA's may reduce interference but that's only because you have a problem somewhere else.