In order to figure out where the airflow is and is not, my mechanic suggested we use a really old technique – tape yarn to the car and see where the wind blows it. Well, we did that. We taped a whole bunch of yarn, courtesy of my charming wife, to the motor, transmission and engine compartment. Then we video taped the yarn whilst driving. We discovered that with the big battery box above the motor, there wasn’t very good airflow from the top to the bottom. Then we removed the rear valence (an air dam just below the rear bumper – used for the now non-existent bumper) and video’d again. Much better airflow. So now, I get to replace the air dam in front of the engine compartment with something bigger, and video again. If this doesn’t improve the airflow, then it will be time for air scoops.
