what you all fail to realize is that that guy is a much better driver than all of you wannabes. he has very good car control, very relaxed driving style. it takes skill to rest your arm on the door while driving on the track. i am sure he could have smoked all of those cars that he gave point-bys to, he just chose to exercise car control skills in the corners with just one hand by the way. this is a very good technique to have in case you need to tighten your belts, change gears or whatever that limits the use of your other hand while cornering.
and grabbing the A pillar allows you to feel exactly what the chassis is doing in high g-force situations.
learn to drive yourself, before you criticize someone that can drive circles around you with just one hand!