Thanks for the awesome info.
I tried the antenna from a Mazda3, as well as an aftermarket antenna I had on my old 3 and even though the threads match up just fine, the base of the antenna overlaps the stock Mazda2 antenna base. That's the main part I dislike about it. The antenna from a Mazdaspeed3, Mazda CX-7 etc fits as well and even though it still overlaps the base, the rubber base part of the antenna acts kind of like a sheath per say which is a bit nicer I guess. Any who, if that's all I end up finding, I'll probably just go with the aftermarket antenna I had on my old 3 which was only about 3.5" long, meh.