I have a 02 Impala LS and it doesn't have the overhead console display in it. I have found one and would like to install it. I took out the dummy and notice that I do not have any other wiring other than what goes to the rear view mirror. My question is #1 can I install the wiring and get everything correct using a diagram or #2 would I be better off to go to GM and have them do it or #3 just leave it alone? Thanks for all replies.