What your looking for is Scosche GM 2000+ , is exactly what you need.
yeah depends on ur car...I have the scosche with on-star for $120 is what i paid for it...erm my local wal-mart just got the new scosche GM 2000 and up W/O on-star for $30 .... honestly, ur not gonna get one for under that, New GM's must have this "chip adaptor" on them, its a lil black box and its gonna cost...
check this site out...2000-Up GM Radio replacement interface with door chime feature at Scosche.com
now i could not find the one w/o on-star or door chime on Scosche.com ( to save some cash ). Maybe they're discontinued because I HAVE SEEN THEM! cause i was pissed to see that i coulda got it for $90 bucks less!
you may have to get it on-line if ur local wal-mart dosent carry the base version...
