So a 3.5mm to 3.5mm cord will be fine? Does brand matter?

If I decide to get the Belkin unit, it says "The Auto Kit also provides an adjustable amplifier and 3.5mm audio-out jack that lets you play your iPod through your car stereo or other audio equipment when using a Belkin TuneCast Mobile FM Transmitter or Cassette Adapter."

would it still work on with AUX?

whats the difference between these two :

http://catalog.belkin.com/IWCatProdu...duct_Id=149006

http://catalog.belkin.com/IWCatProdu...duct_Id=164964