Cop Car Crush! is a mission in Grand Theft Auto 2 given to protagonist Claude Speed by Trey Welsh of the Zaibatsu. The mission is available from the top of the two green Zaibatsu phones in Omnitron of the Downtown District.
Trey Welsh has discovered a snitch in the corporation who's been selling secrets to the police. He hires Claude to steal a police car, pick the snitch, Shady, up, then kill him via the Zaibatsu Car Crusher.
Completing the mission will give you $20,000.