Bribe the Cops Then Cause Havoc

To complete this challenge, you need GTA$5000 and grenades or another weapon which allows you to blow up cars quickly.

Find a parking lot with at least six cars on it. Then call Lester, select the “Cops Turn Blind Eye” option, and start blowing up cars. Usually, it’s enough to blow up six vehicles to complete this challenge. But if it wasn’t, continue to blow up vehicles and kill NPCs until the message about the completion of the challenge appears.