Is it permissible to own a car won in a raffle organized by a Christian charity, especially after disposing of the car and giving a portion of the money to someone else?

The ruling on prizes like these varies depending on how they are obtained. If the prize is permissible to take, and the name on the card is not the same as the name of the person who paid the money, then the prize belongs to the owner of the money.

There is no harm in taking a prize from a Christian charitable organization, as long as it does not cause the Muslim to compromise any part of their religion.