I had the same happen to me and they wouldn't cover it under warranty. Mine barely looks scratched too. I haven't replaced it yet but the sensor is about $180.
The non-premiums were around 58-59k with the addons every dealer seems to put on them, while the premiums were only 60-61k and didn't have addons. I liked the wheels on the premium as well so for an extra grand or two I went for the premium.