Christian you're 3.0 right? I had exact same problem. A new belt won't fix it correctly.
New pulley, from Ford, should be about 43 bucks(was for me). Will fix squeal, and of course you put a new belt on it.
Why not upgrade to Graniteguy's underdrive pulley though, unless you don't really need a few extra ponies. Then you get new Pulley and belt, and part of cost is deferred cause you'd hafta pay X amount anyways.
But my nasty squealing wasn't fixed by a new belt completely, it could still happen. It was something wrong with the pulley.
Well, whatever, lol. You can give me another year's membership or something if you really want to.
Jus give him some wire, a few different sized resistors, and 3 LEDs and he'll be happy.