ive had one for the last 5 years for my license plate. it used to be only for commercial use. they have a list on their website that tells you which cars need it because of special windshields. Here is a sample list.

http://www.illinoistollway.com/pls/p...SHIELDLIST.PDF

you can make the argument that, you have a climate comfort infrared windscreen, which blocks the transmitter. so you'll need the license plate tag.