Can I return a car to a dealer if the car starts to break down hours after the purchase?

Ordinarily there is no such thing as a 3-day "cooling off" period when you purchase a vehicle from a car dealer. Legally, once you agree to purchase the vehicle and execute the sales documents the sale is concluded and vehicle is yours. The sale cannot be undone by you nor the dealer, unless you both agree. It sounds like you may have purchased a used vehicle. If that is the case, when you purchase a used vehicle "as is" there is little you can do to undo the sale or to charge the seller for repairs. Unless the seller included a warranty when you purchased the vehicle you assumed the risk when you purchased the vehicle. It is a buyers responsibility to have a vehicle checked out and to bring a mechanic to assess the vehicle if he/she wishes, and to test drive the vehicle sufficiently and to ensure that the vehicle is mechanically fit. Furthermore, when purchasing a used vehicle one should understand that there is always a risk that the vehicle will require repairs in the future. Unfortunately, sometimes those repairs are required in the near future. Technically, since you placed a stop payment on the check you might have some bargaining power and maybe the dealer will work with you to exchange the vehicle or refund your money. However, legally the dealer has standing to pursue you for the payment and to report you for the stop payment, so be careful. Disclaimer: This response is based solely upon the limited information provided in your question; additional facts may be necessary and may lead to a different response. The attorney responding to this question is licensed only in Florida and this response is intended for informational purpose only and not intended as legal advice in your particular state. Additionally, the response is not intended to create an attorney client relationship.

I'm sorry to hear about the problems you are having with your car. You do have rights under California law, which may help you here. First, if you were given any warranty by the dealer, you can enforce your rights under the warranty. Secondly, even if there is no warranty, California law includes the concept of an implied warranty of merchantability. This means, in your case, that, when the car broke down within hours of purchase, assuming "break down" means it actually stopped running, you should be able to force the dealer to return your money. In order to get complete advice, you should contact a local attorney who specializes in Lemon Law and provide him or her with all the facts and paperwork. Best of luck. Doug Sohn