Car music options...satellite radio, Wifi?

Does anyone use Verizon's new discounted broadband Wifi in the DC Metro area ($50 a month I think) to get internet radio in their car? Is it feasible?

Failing that, how are the satellite radio giants (XM, Sirius) doing? Last I checked their indie/eclectic music offerings were pretty poor, but maybe things have improved.

i pretty much only use my xm for baseball, hockey and college football (although sirius has the big 12, i get the acc, big 10 and pac 10). oh, and for keeping up with the latest in top 40.