Apologies, but I searched through the archives and did not find this particular scenario:

Does anyone use an EZ-Pass with a front windscreen that has the heating coils? I have found that I have about a 35%-50% success rate in my transponder being read and am wondering if the metallic elements may be causing this (by the way, I have the elements, but no means to turn it on - there is just a fake button where it's supposed to be).

I took it back to the EZ-Pass office and they said the signal was just fine, but they gave me a new transponder anyway. I have not tried mounting it in the sunroof as some have mentioned. I use an EZ-Clip, so it ends up being too bulky to close the sunroof shade over it. I am too vain to stick any tape to my windows.

Oh, I am driving an 08 MCS.

Fun story:
When the associate came out to check the signal on my transponder, he sat in my car in silence for a few seconds. Then he said, "I'm sorry, I was just ... blown away by your instrument panel." Then he told me I had a nice ride.