EDKI suggest that tapping the brakes as you land off the second jump is EVEN MORE effective than tapping them before going over it.
Actually I remember braking mid-air as this game tries it's hardest to not let cars get airborne so I don't think they considered about cars braking mid-air despite it being not possible in real life.
You could brake at the end of the jump, but it was easier just to pick and choose where I wanted to brake instead of waiting for it to land since it could easily crash if you were braking while turning at that point.