I stick my VA EZPass in the nook behind the glass cockpit on the left side. Haven't had any issues reading it, or if I have I haven't noticed. I have my plates registered as well for the cameras.My EZ Pass (originating in VA) would not work through the presumably metallic windshield coating. The most effective spot (though not most aesthetic) is the passenger side lower corner. There you will note a section of the windshield that is lacking the metallic coating.
My problem is I have the rare "EZPass Flex" (with an HOV slider), so none of the nice little EZPass wraps fit. I'd like to make one if I can't find one, just because in some particularly hard left turns my pass has been known to go flying.