Got my 05 GT last Friday. Satin Silver with red interior and the upgraded wheels. I've already got two problems with it. My passenger window takes a few tries until it will roll all the way up like something is blocking it and the mustang door plate is coming up on one end of it.

Besides that I love the car and it drives great. Man this thing has got some power. Just a few other things to say: they do look much better in person, red interior is a must have looks great, the upgrade wheels also look really good in person. The exhaust sounds awesome for factory.

Everytime I take it out you wouldn't believe all the looks I get. You would think that I was driving a Ferrari.

I'll try and post some pics on Friday!

 

Just don't roll down your window! Problem solved!

 

Take it back they should fix it at no charge.

 

Try to calibrate the windows; you'll find instructions on how do to it in the owner's manual.

 

Wombert is right.
Recalibrate the windows.

I remember reading something on the windows and the knock sensors.
If the window has a hard time going up with coming back down....redo them.