This mission is given by Sal Gravina.
"Jimmyboy! It's Sal Gravina, how you doing? Listen - you know Elroy Tussle? He heads up a two-bit gang called "The Bombers" or something stupid like that. Those retards stole a bunch of cars last night from Tony, over at the dock. I don't give a fuck about the cars, but I won't have those bastards mess with me. Find the cars they took and wreck them! Anyone gets in your way... well that's too bad."
The mission is located in Hunters Point. Once started, drive to the closest marker to find the first two vehicles. You can use a grenade or simply shoot the gas tanks to blow them both up. Several Bombers will show up and you can kill them or just hop in your car and drive off to the next map marker. Rinse and repeat the process with the third vehicle then drive to the safe zone to finish the mission.