Honestly, you are just going to find the next weak link. Camaro's are notorious for slow windows. The easy fix is to run a separate power wire into the doors from the battery and use a relay so the window motor is powered directly from the battery. It helps them live longer (esp the passenger side). I am not sure you will see the same improvements on a W body, but that is about as far as I would go. Otherwise, you just need to scrape the ice off first.