Looks like you got something going, but in case others are interested, ServeStream is specifically for streaming audio. VLC is a Swiss army knife, just like the desktop client. It tries to do everything.
Slacker has better quality than the crap XM-radio that came with my car, I'm no audiophile whatsoever but even with my standard car stereo the flanging effects, muddy bass and shrill high-end were enough to make me cancel it. I know they use compression, (everyone uses some type of compression) but XM was so bad local FM radio sounded better, that's bad!. Slacker runs an ad or 2 every 10 songs but it's free, if you upgrade to paid no ad's or even DJ's. I also found several more that will work with older Android, 8Tracks is one I might try, I like the idea of listener-uploaded playlists..
EDIT:, Oh, thanks Lxskllr, appreciate the suggestions and fast response, I still might give ServeStream a try, I have till Monday to get everything ready to take it to work, since a 4yr old Coby tablet is worth about $20 I won't cry if it croaks in the 43 degree temps I work in LOL..