Black bars on the cars at motorsport events - what are they?

[gazchap]

A friend of mine took this photo yesterday at Loton Park Hillclimb near Shrewsbury. I went there for the first time a few months back and saw lots of lovely metal, and each one had one of these little black metal bars sticking out of the front, as in the photo.

What are they? Something to do with the towhook perhaps? Only thing I can think of, but I'm used to just seeing stickers with "TOW" and an arrow on them pointing down to it.

[gazchap]

Aaah. Makes sense, cheers.

Charlie: I didn't actually go yesterday, couldn't make it as I was otherwise engaged but I'm itching to go back, possibly as a competitor (albeit not a competitive competitor :P) if I can get everything sorted.