got a question about the rules

I read the rules and am still a little confused. I just want to make 100% sure before I build. I have a CRX and I wanted to know two things. Do the judges go by the hight of the back little window (on the hatch), or the windows on the sides of the vehicle? It looks like my back window line is about 2 inches lowere than the side windows. Second I want to run with my hatch open and front drivers side door open, but I have no wall, Im under the window line (or will be). I will be behind the door pillars and under the window line, but I want to run the port forward and have the hatch open, I know it sounds stupid, but I want to try this, and If my numbers are crazy high, I don't want to be dissapointed because it isnt legal. Any help would be great. I plan on running 1801 and up pro stock.

under the back window (hatch)