On my road trip to Rochester there was a car infront of me with a Cobra. XRS model couldnt tell which one.. Anyways The K band drones were out and I was using this person as my rabbit for a while. We were going 85-90. I was about 10-12 car lenghts behind her. All of a sudden I get a K band alert and about 5-7 seconds later I saw her break it. I was like I bet you in a few seconds here she will slam on her breaks and sure enough she did!