Rental cars often have a box on the windshield that is designed to hold an EZ-Pass accessibly. It has the added advantage that you can easily open the box to use the pass, or close it fully to have it not be read. I don't know where a regular person would get one, though. If anyone knows, I'd be interested in this as well.
1993 Ducati M900 Monster "Patina" (265,000 miles, killed by minivan 30Oct17) -- 1995 Ducati M900 (wife's bike) -- 1979 Vespa P200 (daughter's scoot) -- 1964 Vespa GS160 (160cc 2-stroke) -- 1962 Maicoletta scooter (275cc 2-stroke) -- 1960 Heinkel Tourist 103A1 scooter "Elroy" (175cc 4-stroke)