I did too, shot up the courier while on the ground. I think I landed ahead of it so I can shoot at it as it came towards me. Also, there was a certain order to them too or else one of them would end up being out of reach if left to the end. Frustrating mission.
Hardest one for me still was the one where you had to fly and catch up with a plane carrying mobsters. Took me so many times to do that one
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