Fact: The first motorsport event that I ever attended involved a demolition derby. It was 1986, I was 12, and I was invited along by one of my mates from school and his dad. I think the demolition derby part of the evening was the support act to the main event, but somewhere along the line I have forgotten what the main event actually was.
Given how much dirt was flying around the place, I have to assume it was something to do with speedway racing. What I do remember is that I was decked out head to toe in pastel green - a pair of pants and a matching polo. This, remember, was the era of Miami Vice, and being a 12-year-old of limited means, such gear was the closest I could get to dressing like Don Johnson. (And forget about the stubble part - 19 years later, I still can't grow a beard).
These were my coolest clothes, the threads I only pulled out for special occasions. And by the end of the night, they were absolutely trashed. We'd scored a prime viewing spot right on the fence, which meant that my iridescent snot-green gear was right in the firing line for all of the mud that dozens of spinning tyres sliced into the crowd like soggy golf balls. I was never able to wear the pants again.
I got over the loss of the green pants years ago, so that can't have anything to do with the fact that I have not been to a demolition derby since. I haven't been boycotting them or anything, but they just don't figure all that heavily on the landscape of motorised entertainment in Australia - I think that Demolition Derbies share a common ancestor with Monster Trucks, which we also don't see a lot of over here. But they feature semi-regularly on The Simpsons, which is one of the great barometers of American popular culture, so that is enough to convince me that Derbies have a kind of niche foothold in the US.