This mission begins outside a pawnshop for a reason, but with 2 standard IED’s and a Proximity IED you can finish this mission with ease.
As soon as the mission begins you want to run south to the highlighted path, beating the convoy there. Across the street is a truck that you want to place an IED in front of, on the road so that the truck won’t explode, and then place a Proximity IED further along the street (this will cause the lead car to drive over the first standard IED but die to the Proximity IED).
As the convoy arrives you want to hide behind the truck so you can target the standard IED and when the target truck begins to drive over it you want to set it off, DO NOT DO IT BEFORE THE FRONT WHEELS PASS THE BOMB OR IT WILL BE TOO SOON.
The lead car will be cleared but the truck as an Enforcer who will pop out, so toss another IED or Proximity IED down to deal with him. This will actually be all you need to do, but if you want to finish off the few enemies left you need to do so fast before they call in reinforcements.
Killing off the enemies or escaping will complete the mission.