Aux Port Issue

At first when my audio problems started, I thought I had a blown speaker on the front drivers side. I notice by wiggling the AUX cable slightly, the problem would be fixed. When the problem got worse, I bought a new cable but the problem persisted. The speakers seem fine when listening to the radio and now the only way i get get all of the speakers to work is if the cord is in the exact position. Another thing I noticed is when traveling long distances, I'll plug my phone and iPod into my dual DC outlet plug, The speakers work almost flawlessly. If I unplug one, the sound quality will decrease. If I unplug both, the problem is back where it started. I took my car to the dealership and they told me it's either the port, or the radio. So they charged me an hour and told me something I already know. There has been previos damage behind the dash. The temparature dial had been pushed into the dash and may have damaged parts behind it

I have to ask why so many people want to run their audio system with their phone