Had none of the problems, but I'm using an Creative Sound Blaster MP3+ external usb card.. Works like a charm! Extended the usb cord 5m, and ran it into my glove compartment..
I have a Audigy 2 NX.. and if I run its power wires across the audio wires.. I get the ground loop problem... you just have to isolate the audio signal from the power signal..... IE.. dont run the wires next to each other if at all possible...
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Pentium 4m 1.5GHz|MB896|Roadie Extreme|XM-Direct|Rikaline 6010|T-View 7"|Streetdeck|160gb Western Digital|1Gb DDR2-533 Ram