Signed a contract on used car 2 days ago. no money exchanged hands and i did not take poss. of car.am i stuck?

No you are not stuck. Tell the person you have changed your mind. You have at the least 48 hours to cancel any contract. You should be fine since no money has changed hands and that you have not taken possession of the car. If the person complains about your decision, advise him your lawyer states that you could cancel the contract since nothing has changed hands.