I had the same situation with my car and I wanted to get rid of the lighter but have a cap to cover the socket like the one in the back. I checked at the dealership and the cap costs about $5 and is part of the plastic trim ring around the socket. The parts diagram also lists a separate part number for the aux socket versus the lighter socket so I bought that for $10. The lighter socket has two extra tabs inside that I assume catch the lighter when it pops out. The aux socket is nearly solid. I did not get gm's cigarette lighter removal tool so I was glad I had the extra socket. It is a pain to push the little tabs in to slide the socket out witout mangling it. Once thats out, you pop the new ring and cap in the trim panel, hook up the new socket, and slide it in. I know, I know, it's the little things that excite me.

 

thank you for the information i haven't been able to figure out how to get mine out on the dash yet to change it!! thank you