The Oil Slicks From Your Arse powerup is pretty self-explanatory: it generates a smudge of oil underneath the player's car. This is practically useless, because a puddle of oil will never do any kind of damage. The only potential for this powerup is that the opponents can lose a bit of control when passing over these. Or, it could have another silly use. A really injured player can place a puddle underneath them to pretend they're wasted. When a (human) opponent passes by, ignoring the wasted foe, the player can chase them and scare them... Yes, this powerup is that useless. Also, using it in mid-air completely wastes a use in Carmageddon II, and generates a puddle on the ground directly underneath the player, in Carmageddon: TDR 2000.