So so fake IMHO, the height of the bonnet means he would have needed to flick the back of the bike up to avoid striking the BB / Crank and he does not appear to do so, also I'm not sure how in the time it took for the driver to get out of the car he managed to stop the bike, unclip and stand on a slippery car roof without falling off, not to mention attach the mounting clamp to the bike, which suggests the footage is heavily edited.
Showing the full Video from the outside of the car would have been more impressive if it was real... Danny MacAskill he is not.