I've got a 97 P38. I'm very happy with the stock sound setup in the truck but would like to connect my phone for mp3 tunes. Is an FM unit plugged into the antenna line my only option if I want to keep the Clarion head unit? Anyone else been creative and have another solution? My understanding is if the head unit is replaced, there is an issue with the amps in the doors and how they are designed and the maximum power they can handle.