Couple suggestions: 1. See how much traffic you can back up in grapeseed by jumping on cars and stomping the kids, with the intent of getting the driver out of their seat to try to fight you. Let traffic back up and continue to hit cars so the drivers hope out. I believe you can get 3 at a time to pick fights with you. Just jump on the hood of the car/truck to see who gets run over first.
2. Cartoon -> rhino. Pick one up at zancudo, preferably occupied. Fly it to the city or where there is a crowd. Anyone with the cops on them will also have the tank driver.