Audio Systems: Ford/ Mercury Premium sound, sony head unit, rear quarter panel

Question
I have a very late 1989 Mercury Colony Park Wagon and it has premium sound written on the door speakers but it has the non premium plugs for the head unit. I am trying to instal a new sony head unit. My question is... Is there a simple way to bypass the premium amp and make this system work? I Bought the wiring adapter to fit the plugs I have but when it is all hooked up all I get  is a buzzing/hissing noise from the speakers. I also tried unpluging the speakers to test the cd player but then it wouldn't even power up. Any insight would be greatly appreciated.       Thanx, Rich  

Answer
To answer your question...there is no easy way to bypass the amp on this vehicle.  If I recall the amp is located in the drivers side rear quarter panel behind the plastic.  Running speaker wires from the new head unit and testing and finding the speaker wires at the factory amp is the best way get some tunes back into your car.  It's not easy, but it is very possible to do.