What do you use to clean your windows? The old wives tale of vinegar and water sure doesn't work. Makes the window sticky so it sticks to the rubber. I only know this because my wife used it last time to clean my windows. My motor also runs slow with weight. I don't think the motor is powerful enough to move 200 lbs + the seat weight. If it is really slow, then I agree with the above...the motor is going. As far as loose, check your rails and make sure they are torqued down.
This is old but.........
Mike was right about the felt thing (I havent noticed it on stangs but have on GM's). I couldnt get the right part and rigged something together. Bonding a little chunk of Microfiber towel to the piece would probably work well.
The slow movement and other issue could be related.
My seat was slow when I got it and within the first week of ownership, it got tired of my weight and crapped out (in the fully rearward position - I was doing an install). If people have motors on the outs, I suggest that you only move the seat when you're not sitting in it. You can even help push it in the direction you want.
Oh, I had a broken mount on the power track - ergo slop. I looked at it - it looks like they cast those mounts from soup cans.
I get a light vetical scratch on the tint on my driver side window thats it. It doesnt really bother me because i have the tint redone every few months after the police give me a ticket.