i heard that the autophile http://www.theautophile.com was the *best* place in the bay area but they don't really do installs for under a couple thousand (which includes soundproofing the environment, the best cabling, special car battery, etc). they might have a lot of disdain for an MP3 player but they liked my old unit. the estimate from them for another amp, 4 speakers and install was about $8500 i think.