has anyone gotten this acheivment and hom many secondary objectives are there in this game. i have 41 out of the 43 acheivments and i can not get this one. i have beaten this game twice in single player mode and once in quick mission, and yet to get this acheivment. need some help please

the secondary objective is to nuetralize the fleeing vehicles in each level. it tells you in the narrative secton of quick mission which missions you have already completed the secondary objective on.