When my iPhone 5 is connected to the car's radio via USB cable

I use my phones bluetooth for call purposes, but i connect my phone to my radio via a USB cable for charging and if i want to hear music from it. Recently, it has begun to act weird. I answer a phone call, and it starts playing my 1st song in aphabetical order, during the phone call. how do i stop this? It just started about three days ago.

Second Issue - When charging from any source, my reception is diminished must worse than before.. Why?