These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Cult Classic: The series has a large fanbase constantly creating new downloadable cars, tracks, pedestrian models, tools and game mods. The new game is being developed with the help of the fanbase.
Demonic Spiders: Police cars in the first game, which were seriously better than your own car until the endgame. If one ever decided to chase you, stopping it often took as much time as all your opponents combined.
"Funny Aneurysm" Moment: In the PC version, which came out in June 30, 1997; One of the drivers was named Die Anna, which seems harsh consider how Diana, Princess of Wales, would die in... you got it.
Also, the Electric Blue. It will instantly zap any nearby pedestrians as you pass by. Great for clearing the entire level of pedestrians. Unfortunately, you can only get it after having completed the game. Or by cheating.
The stone car powerup. It essentially turns every single hit into a one-hit kill. Stack gripped tires on that, and you could launch whoever you hit halfway across the map.
Screwie Lewie's car/airplan/mole machine, whatever it's called. Compared to most cars by the time you can get it, it has tremendous durability and speed and better acceleration and handling than it should have, plus it seems the airplane parts help stabilize it so it almost always lands right side up when rolling.
The Opponent Repulsificator from the second game if used correctly can bounce cars into walls at high speed.
Good Bad Bugs: Carmageddon 2's punching glove powerup could, almost certainly unintentionally, be the deadliest powerup in the game under the right circumstances. If your opponent was leaned up against a thin support beam (or anything else that's reasonably thin and unbreakable) when you used it on them, it would literally tear their car in half as it tried to punch them (since half the car can't go anywhere, the other half does). Very hard to pull off, but an instant kill.
Scrappy Level: Ramp Rampage. Fifteen laps on an annoying industrial level with several choke-points that tend to get clogged up by the stupid opponents; very little starting time and few conveniently placed pedestrians to run over for more; no good long stretches of road to set up head-on rammings for wasting the opponents; and at least half dozen incredibly annoying cops.
Carmageddon 2 featured a lot of these sadly, in order to unlock more maps you had to play unreasonably stupid, boring and annoying levels where you jumped around on roof tops and destroyed satellite dishes, which for many killed the joy of the game, since you only want to play through the first city so many times.