"Just whip out the Krukov and make sure you take out the Carnales with the rpgs. Dont worry about the other cars. The first one with an rpg is directly in front of you when Dex yells to take them out. The second is on the roof right next to the first one. The last one is on the white thing to the right of the ramp. After Dex makes his rounds and he drives up behind the plane use either your RPG or the Krukov to take it out. Dont worry, took me a while too."