If the car dealership is now contacting you about wanting to cancel the purchase of your vehicle where you were paid $8,800, you are under no obligation to respond. By your actions with the car dealership you have a sale where money was transferred to you and title was transferred to the dealership.Since a stop payment has been placed on the check, I suggest that you consult with an attorney experienced in contract law to assist you in your matter. The dealership had the ability to have one of its mechanics to thoroughly inspect your vehicle before it was sold.