Couple things in mission 13 *Spoilers

1. Some of the enemy spawns appear to be inside buildings, at least one truck spawned stuck in the side of a building (another building was close by making it hard to find but my door gunners got it).

2. Convoy does not move out after reforming to backtrack and go the other route. Message "we keep moving" or similar is played, but convoy remains stationary. Tried to nudge it by flying away, got a message asking me to come back followed by another "we keep moving" but no movement. Had to skip the mission.

Update - not an idea work around, but if you shoot the convoy while they are stuck they go into their disperse mode (they appear invincible so you don't damage them). If you wait through the disperse mode, they continue toward the objective.

Another thing, the bridge was not actually destroyed by the explosion. A scenery destruct trigger could make sure you get the visual "bridge is destroyed" effect.

Yes, just did some quick testing, scenery destruct and the triggered explosion (on the same cause) works well. I'm glad I looked into that for my own missions!