Mazda OEM window guide bushings eventually break down and gunk up with old lubricant. Replacing them with more durable and slippery delrin parts brings windows back to a smooth glide.
Do not over-tighten the screw because and risk breaking the glass. I had to sand the bottoms of the bushings a little bit shorter so that they could spin freely with the screws tightened.
Supposedly Honda Shin-Etsu silicone grease is the world’s best lubricant, but I just used Super Lube.