I'm not trying to hijack the thread. But, I have a related issue and I don't feel it's worthy of its own thread ... maybe it is?
I sometimes like to play mp3s through Radio 10 from my notebook, which has a high end sound card. Everything is hunky dory

That is, while the notebook is on battery power. If I attempt to power the notebook via power inverter I get noise from the car's electrical system (ignition) over the speakers. The notebook has two internal batteries and can run off of them for something like 5 hours. But, is there an induction filter or something which would allow the use of the power inverter for long trips? I asked at Radio Shack, and the employee there did a good impersonation of a 1950s Sci-Fi computer given a paradox to analyze.
P.S. No problem with volume using the notebook.