I just drove in to Austin, and I realized I left off two whole music genres- important genres, if one is driving through a small town in the south: country and Christian. Since I am less familiar with these genres, I'll keep this list to those groups/singers who are good enough for the "rockers" of us to listen to.
*House of Heroes- one of my 2 fav bands and you'll find them on a Christian rock station. very good music to drive to!
*George Strait- can't go wrong w/ George.
*Alan Jackson- he's just a fun, country boy.
*Skillet- Christian heavy metal, on par w/ Korn.
*Abandon- the Christian's answer to The Fray/The Killers
*The Contact- a better, wiser version of Abandon (and The Fray and The Killers for that matter).
*Linda Ronstadt- wonderful voice, and she sings in many different genres, but you probably won't hear her on the radio unless it's country.
*Project 86- Christian heavy metal w/ a Mike Patton feel.
*Children 18:3- awesome Christian punk, a la Youth Gone Mad.
*Lucinda Williams- the kind of country you might listen to on a lazy summer afternoon.