(OT) Car stereo adoptor "thingie" ????

generic.homeowner · 2011-11-25T14:30:41+00:00

They sell some sort of device that you plug a portable MP3 into it,and that thing sends the music to a blank radio frequency so the mp3player can be heard on the car radio.What are these things called? I'd like to get one, but dont have a clue what to shop for. I asked aguy in the electronics dept at Walmart and he could not figure outwhat I wanted. (Of course I didn't expect anyone with knowledge atWalmart), but thought I'd try. I suppose this is something to buyonline, or maybe Radio Shack...But first I need to know what they're called....Thanks