Ding ding ding? really? I'm just happy to help the guy, not receive credit. Judging by the responses, no one else saw your suggestive post either. But, I digress...
Irrelevant...the point is to use a toothpaste that has a good amount of abrasives, and when combined with a buffer, they will remove the crap on a windshield quite effectively. The only reason I said not to use gels is because they tend to have fewer of the good stuff.
I must have missed that post...180 degrees probably won't make a difference since it's still horizontal. 90 degrees, on the other hand...I concur with your rotating AFM 90 degrees. Since that is free, it would be my first choice.
I'm going to take a stab at this...With the trap door AFM, I believe they can only be installed one direction, and that's with grid pattern up, or horizontal. You have it mounted vertically, and from what I understand, it will not work properly that way. Messes up the readings somehow.
We had a boat with a deteriorating aluminum frame for the windshield. The corrosion stained the windows something fierce, but nothing we used to remove the stains worked. Finally, someone suggested a buffer with toothpaste (not gel), and voila, stains gone. In fact, it was surprising how fast it worked.