I work at Guardian (
www.guardian.com) who makes the glass for almost everything (but mazda). Six is right, since they were screen printing the part anyway it literally costs about 1 penny or less to paint that area where the mirror button is. It does create a visor effect and the little dots are just the standard automotive pattern. It blocks some of the sunlight, shades the urethane seals from all of the light\heat. Some companies paint a completely solid frit (no dots, just all black) near the mirror button as a shade, but mazda decided to keep some of the visibility. The reason the dots are much bigger on the "a" pillers is simple, the driver wont be looking at it up close and the dots wont obscure his vision even if they were bigger. Its all about the AS1, AS2, and AS3's. AS1 is a windshield and you will see a little as1 writtenabout 6 inches from the top of the windshield...basically means they arent allowed to shade below the mark. Also AS1 are laminated for your safety. AS2 is a side lite, (tempered to be able to shatter in a million pieces to not hurt you, its to your driver's left and right side. Visibility is important on those but not as much as the AS1. AS3's are side lites or back lites and pretty much have alot less rules, you can paint them almost completely, put big old dots. Some companies use the paint to hide things their engineers did when they designed a vehicle and didnt think it through.
Ahh well, thats more than anyone ever needed to know about automotive glass!
Oh yeah, the quality of the glass is ok on the mazda, its made well, but the frit dots being diff sizes is just dumb design, and the final logo that they paint\sand blast on the driver and passenger windows arent parallel to the door jams, which is REALLY SLOPPY. It kind of annoys me but it IS purely cosmetic, as the glass is made well.