Thank you all very, very much!

After doing some relatively unscientific and quick, blind switched comparisions of Wav, 160, 192, 256, and 320kbs MP3 files, played back on my best disc player, I have concluded:

160 is the only format I don't want to use. I also had a very, very hard time telling 256, 320 and wav apart from each other. Probably, if I am honest, for the material I tested using Steely Dan's AVA and Nora Jones albums, 256 is probably plenty good for my car and also probably indestinguishable from the wav for most serious listening.

So, since I can always just put the actual CD on if I care in my primary system and my car, I'm gonna use 256kbs (with VBR?) for recording my music on the RioCar. This serves both the music server and audiophile wannabe in me nicely.

Thanks again for all your help!!!