If it has wheels - whether it's a retired school bus or a pocketbike - it will be raced. Here are five ways to get you giggling, have a thrill and, in some cases, attempt to bend the laws of physics.
Top 5: Crazy motorsport creations
For most of us, a lawnmower means only one thing: drudgery. But ride-on mowers need not fill your weekends with misery - you can go racing on them. Insane, yes, but you've got to admit, potentially a great laugh. It's becoming increasingly popular in the US and Europe and, before you ask, the blades are all removed before a mower can be homologated. Yes, lawnmower homologation - we can't believe we're printing this stuff, either. The cheapest form of motorsport and quite literally the greenest.
School bus racing
Vehicles don't come much more iconic than the American yellow school bus. So what else do you do with them once they're retired, other than race them into the ground? Often weighing more than 7,000kg each and measuring up to 15m in length, they're not the most nimble of racers but they certainly draw the crowds, with thousands flocking to see them battle it out in the US. Races are usually held on oval tracks but, whatever the venue, there's always carnage. Cheap, fun, mental - what's not to like?
Super Truck racing
While Americans race school buses, Europeans are rather fond of tearing around tracks in articulated lorries. Well, the cabs, at least. Many of these diesel-powered machines develop 1,000hp and 3,000Nm of torque and, once the trailers are uncoupled, are terrifyingly fast. A race truck will actually out-accelerate a Porsche 911 up to 160kph and officially it's a "no contact" sport. But the sheer size of these things makes that impossible. Cue plenty of bent metal and a thrilling spectator sport that makes F1 a bit dull.
Perhaps this might be the winner for the form of motorsport that makes the competitor look the most ridiculous. Riders precariously balance on minature motorcycles - about a quarter the size of a real bike - racing each other in full leathers around a circuit. But don't be fooled by the bikes' diminutive size; though racers might resemble a circus bear on a bicycle, the bikes are capable of more than 120kph. Plus, you know who raced pocketbikes? Valentino Rossi, that's who.
If a pocketbike makes you look ridiculous, sidecar racing makes you look positively insane. These specially built, three-wheeled bikes have someone at the throttle and controls, driving the contraption, with a passenger hanging on for dear life in the sidecar. But the passenger isn't just along for the ride; he or she must use their body weight to help the bike in the corners by leaning extremely into a turn. It takes a special kind of person - ie, crazy - to hang out centimetres from the asphalt at speeds of up to 260kph.