I remember seeing a link to how to adjust the height of the hood at the four corners. I remember the two front adjusters had a plastic type nut that just rotated about a quarter turn. That unlocked the height screw. What I don't remember is, does the screw adjust up and down by turning it or does it just pull or push up or down followed by turning the big nut back to lock it? It's hard to tell by looking at it. :?