hmmm...motorsports test facility in back yard...nice!
one safety note: side window needs to be rolled up, no more than 1" open. this is std procedure for rally/rallyx, it keeps rocks and debris from coming in windows when you're flying sideways (dirt clods can pack a punch, even when you're wearing cranial prophylactic), and most of all, if you roll the car, window keeps arms from flopping outside the car and subsequent Bad Sheet from happening.
windows up is such a key safety factor that you can be heavily penalized if spotted on a hot stage with windows down.