The dealership wanted $95 to put one in, but he managed to add a 3.5mm audio-in port to his car stereo for just a couple of bucks. The connector on the back of his head unit is a 2×4 set of pins ...

Now Scosche, manufacturer of car audio accessories, ... Included in the kit is a 30-pin dock connector cable that connects the iPad into the system's USB port and auxiliary input.