Just go to the track at night and look around then you'll have a scene where you're eavesdropping on scar
Ok so (just got done playing through it another time) you have to at least have met jester till you were able to speak with him freely. Go to the track at night and you'll eavesdrop, (I guess it is random) go back to jester and exhaust all of the dialogue options then the next day you'll ba able to begin infiltration (which is basically the battle with tank and scar)