Just stuffed this random thing I found in a junk pile into my car. It’s an FM transmitter with bluetooth, so you can connect your phone with bluetooth and it will beam it to your radio. It also plays MP3s off of SD cards or flash drives, and you can direct-wire it through an aux jack instead of the FM transmitter, as I have done. It’s amazing.
Sit in car, turn on car. Radio turns on, this thing turns on, 5 seconds later I hear ‘bluetooth connected’ and then ten seconds later it starts playing my music. Voice commands and Cortana all work through it, and I can read and respond to texts without physically touching my phone. I’m never having a phone without BT again.