What is the ruling on selling a car in which a crack in the chassis was later discovered, after the seller swore that it had no defects, and is the buyer entitled to get his money back and return the car?

If the defect in the car is established before the purchase, the buyer has the option either to annul the sale and reclaim the full price, or to keep the car and receive compensation for the defect (the price of the reduction incurred due to it). This is the view held by Ibn Qudamah, based on the principle that the original state of a contract is soundness, and a defect contradicts the essence of the contract.