Is it permissible for parents to perform the Hajj obligation with money from a car won by their son in a coupon draw?

The ruling on this prize varies depending on how the raffle coupon was obtained. If the prize is permissible, then your brother may benefit from its value, and he may give some of it to your parents for Hajj or other purposes. However, if the prize is forbidden, then he must repent and dispose of its value in charitable endeavors and for the benefit of Muslims. He may not benefit from it himself unless he is in need.