Not much time at all, I agree. But any heat that can-be avoided is good when it comes to intake air-flow. I think more relevant is the air flow issue really - after studying the video it became clear just where the air-flow is strongest and weakest. That was my starting point for deciding where to place my intake scoop. The video evidence clearly shows the top of the rad cowl isn't the optimum position.
Just do a long, fast summer evening drive to discover where the airflow is strongest - its the points where all the dead insects/bugs are.
