Whatchamacallit?

The icy thing you see located behind my car tire is what causes drivers up here alot of angst. A guy I work with broke a toe once kicking it the thing off. They melt during rush hour, fall off cars, and then refreeze to create a nice patch of black ice. They leave nice chunks in parking lots and on driveways. But what IS it called?

I've heard it called a clunker, a chunker, an ice berg, and a tire berg. One local radio station was having people call in reporting what they call them. A tire dam? A mess?