I just read this topic and saw all the suggestions about Mission 7, but I'm still stuck!
The flir just won't work so I'm following @Badger633's suggestion and using GMT radar. Mav still falling short of the trucks (twice I hit the first truck actually).
Looking at the Mav screen, when I cage/uncage it looks like it is locking to a lamp post instead of the trucks. I tried approaching from few different directions, nose diving, higher and lower altitude...nothing seems to work.
Just wondering if anyone has a work around....
Edit: Including some images to ilustrate better what I mean.
Locked with the radar:
In the flir it shows me the truck being tracked:
Mav is good to go:
Mav doesn't seem to be locked on the truck though (truck in red):
It always fall short (trucks in red and aread of impact in yellow):