Around 39 minutes to beat. The first part is easy since most of the targets are worth alot, especially aiming for the oil tanks and causing big explosions. The second part is initially tough since the trucks seem to completely disappear once they go off your radar, which happens frequently. The key is to look at where they last appeared on the mini map and try to face that direction and head toward that area. When you are close enough to a truck it will allow you to lock on to it with your missles. One truck is in a valley and can be tricky to hit as well. I fucked around and suicided after it said mission completed so had to redo the 20 trucks section.