At the car
Howard looks nervously at the zombie clawing at the window and then at Jacob. "We need to get out of here, and this car is in the way. The parking brake is on, and I don't want to risk damage to Andrew's car by pushing this car out of the way with it. Hear that, Andrew? I'm taking good care of your car! So, Jacob, you try to keep its attention here, and I'm going to go around and open a door on the other side, then we can kill it...again...as it turns around and comes out."
Having said this, Howard does it. He taps on the window again to attract its attention, then backs away from the car, far enough away that he thinks the zombie is likely focused on Jacob now, and then circles around. If the zombie is still distracted on one side of the car, he'll run up and try the door on the opposite side. If it sees him before he can open the door, he'll open a back door, so that the moment that it takes the zombie to climb into the back seat will give him enough time to take hold of his paper cutter blade, ready to strike.