Alright, Here's my attempt:
Arstotzkans have always been mechanically minded, so when cars became commonplace, people naturally decided to race in them. Then they began tinkering with the engines, trying to eek out just that much more horsepower, and when fuel injection and turbochargers became a thing, they tinkered with those as well, and the motorsport craze just took off. If it has wheels and an engine, Arstotzkans will race it, from souped up motorcycles to custom-built high-performance drag racers, and anything in between.
You can find any type of racetrack in Arstotzka, from rude dirt oval tracks to expensive asphalt shrines to the sport. And often, you don't even need to go to the track to catch a race; rally races through the streets of the capital are commonplace. If you want to watch a race, you generally only have to stay still for 5 minutes.
No matter where you go to watch a race though, rules tend to be similar. Arstotzkan races generally only have a few rules: No sabatoging or intentionally wrecking the opponent, you must stay on the course(no shortcuts!), and you can't use weapons to attack your opponent. Other than that, a racer can do anything from using special fuels to boost his performance to attaching rockets to his vehicle(one enterprising racer attached wings to his car and attempted to fly above his competition. This was...less than successful, thought he resulting crash and fireball was pretty hilarious.) Arstotskans also don't bother with silly things like safety equipment, and only have the rudest crash barriers in place to simply keep cars from flying into the stands(racers often claim safety is for pansies and tiger fucker Moskurgs). Half the fun of watching Arstotzkan style racing is for the spectacular crashes, with the other half seeing what crazy contraption a racer has come up THIS time to give him any perceived advantage while staying in the letter of the rules. Of course, this wouldn't be Arstotzka if races weren't capped off by a shower of fireworks(though the rockets are often overshadowed by the fireworks on the track).