Destroy 100 vehicles in "Jimmy's Vendetta."
This can be done both in and out of missions. You can either shoot the gas tank or blow them up with a grenade or molotov. You can check your progress by opening the Game Statistics from the pause menu where it's listed under "Cars destroyed."
- Although the game statistics list them as "Cars destroyed", they have to actually blow up to count. Crashing a car until it's "totaled" will not count.