I had the same problem and i finally figured out that the kit was for a earlier year and put in the wrong box. It was from the same company. The window angled too much when it came all the way down and then curved too much at the top. It turned out ok they shipped me the right parts. Just a pain. I was working on a 40 and had a kit for a 37-38. Also check if your right left is correct. I have been a real duffuss complaining only to find out I am putting the right on the left.....
If you only using one make sure they shipped you the proper side.