The toll booth read mine from inside the glove compartment.
I was trying to prevent it from reading so as to not incur a fine for towing a trailer with my single-vehicle EZ pass. The NY Thruway Authority could count axles, but couldn't figure out how to charge you for it at the time.
Funny part of the deal was I had stopped to get a ticket and the light did not indicate. The attendant looked at his screen and said, "You've got an EZ pass. Why'd you stop?"
He said that the readers could sense the EZ pass no matter where it was in the vehicle, unless it was sealed in the special bag.
Now they count axles and charge you based on number of axles.