I dont have a reverse cam so I left the reverse wire disconnected, as for the gps antenna, you can mount this under the dash surface. If you look into the open hole with the radio removed you'll see up and forward the defroster vent plumbing. there are two flat surfaces there that are just about right to put the gps antenna on top of. I have a pioneer that had a magnetic antenna and a supplied tin sheet (about 3"x3") with adhesive back. This I stuck to the top flat surface of the vent plumbing and then dropped the antenna on to that. This way nothing is visible from outside the car and my gps still works as intended. Someone asked about the mic too.. not sure if it was you.. but that one I put on the top of the A pillar trim. Somewhere I posted pics.. just cant remember where off the top of my head. Hope this helps, if you have any other questions just drop a line and I'll answer best I can.