So, I know that most transponders for tollways are supposed to work better in the little black dotted area by the rear view mirror. But the little tag for e470 in Denver is supposed to be in the lower left windshield according to their officials. Of course I have discovered it doesn't work there. Possibly because of the slope of the window or else some factory coating, I don't know. What have other Denver folks found to be the solution? Also note that I currently am a scofflaw and do not have a front license plate.