Car Stereo

I have been researching car stereo head units that read usb thumb drives in particular, and probably mp3 cds as well. i thought the sony cdx-gt610ui was a good choice since c-net gave it 8.4/10 stars, but the moddedmustangs.com guys say sony is garbage. wal-mart has a sony gt61ui for around the same price as the cdx-gt610ui, but not sure what the differences are. looks like it supports a pre-amp sub-woofer connection? it is around $165 list, but the pioneer deh-p690ub supports usb with an included cable, but lists for $219. both are really a little out of my price range, but i am not going to by the virtual reality vr3 nor am i going to get the boss 630ua which are apparent junk. some other people said the sony cdx-gt610ui had alpine-quality sound at a lower price. i might at some point consider the addition of a sub, which i am assuming should really be driven off an amp? or can i plug the sub into the head unit or drive it off the rear speakers? suggestions . --steve

Alot of people do not like sony, personally i have nothing against them, their specs look great. pioneer premier and alpine are amoung the best out there, with kenwood right on thier heals. for usb i think that knocks alpine out. kenwood has a nice deal hear. it includes the installation hardware for your specific vehical and the wiring harnes.. so its a better deal than the 180 price tag reflects. because the kit is required.http://www.crutchfield.com/s-ocqhkxchcn8/app/product/item/main.aspx?g=300&i=113kdcx491&c=3&tp=5684