Mission 42 – Locate and Destroy Moonshine Trucks
Unlike every other mission up to this point, this mission doesn't end- you can keep destroying trucks forever. Not that there's any reason to- your only reward is damage to the racket, and there's only so much of that you can do.
As for methodology, just drive around until you spot a truck, then take it out with a grenade or sustained machine gun fire. Rinse and repeat as needed.