- chickenlittle
- |
- Fabled Mythic Member
For the first pair, you'll want to be across the bridge and 3/4 the way to the group of enemies between you and the Marines. Shoot both of them with your pistol until they're both smoking - but don't kill them. Once they're both smoking, attack them with your pistol, 2 shots per vehicle. If you use half your clip before killing one, reload.
As for the rest, there should be a pair when you first get out of the tunnel, and a new pair after you rescue the first two lifeboats of Marines.