I did not need the 12 volt plug. so, I tore mine apart and did a custom install. I wanted the USB and volt gauge They installed into my dash very easily. I had to drill a hole for the gauge. Not a big deal. I have reverse sensors on my truck, I don't even know why they put a switch on it. I made the switch disappear and dropped the USB port into that slot. It looks great and the wiring was a cinch for me. I will add photos later.11/23/2016: update. So last night, I had both my Samsung and iPhoneSee full review