Just get some of the square PVC...
I do dig the power panel, It would be a good project to do in the CD changer slot. I know Bart has an inverter there, and I copied him and did the same. Mine is not cleaned up like that, I have a ton of aluminum though...another good winter project I think.
You can get 700 watt inverters at HF pretty cheap. Mine is big enough to run my electric impact or a 3gallon compressor. The impact does trip the inverter every once in a while, but hey, for 30 or 40 bucks, no worries.