Suppose a Car/Van is launched into space with you. Suppose you would like to do 'Surf' on the car roof like Marty in "Teen Wolf". On the earth, if car accelerate up to 30-50 or 100 mph will make Marty fall down because of air friction and because Marty is not "anchored" to the Van.
But what happen in empty space if car accelerate and I'm not anchored to the car roof ?
Will I get "car motion/speed" just because I'm lean on car roof ?