Your rights in this respect are very dependent on the laws of your state. Hence, your should not delay in seeking the advice and consultation of a skilled attorney in your state.
The consumer protection laws can vary widely from state to state depending on the nature of the sale transaction. Certain federal consumer protections apply if the vehicle has substantial defects that cannot be repaired (Magnson-Moss Act); but that doesn't seem to be part of your concern. In Georgia, except for a certain categories of transactions where fraud is rampant (door to door sales; telephone sales; gym memberships among them), the rule is buyer beware. Ordinarily in such circumstances, you would have no walk away rights after closing a transaction for a candy bar or a car. Your mileage may vary depending on your state law. Fraud in the inducement might be another basis to rescind a transaction, but the burden is generally higher than simple "buyers remorse."
If you do have a protective state law for consumer transaction, it would be reasonable to expect the recission period is likely very short, and the requirements strict. Thus, don't delay in obtaining legal advice in your state.
Best of luck to you in resolving this issue.
Note: This Answer and any information contained in this answer is not intended to be treated as legal advice, but is offered solely for information purposes; And, this posting does not create an attorney-client relationship or privacy privilege of any kind. This attorney licensed only in Georgia.
Generally there is no 3 day right to cancel a car sale unless there is something written down in your sales paperwork that gives it to you, but you may not be stuck because there may be other ways to cancel the sale. In a used car sale, your legal rights are mostly determined by the paperwork that you sign. Look to see if anything was written down about any kind of right to cancel. Also there’s a federal law that requires all car dealers to post on the window of all used cars they are selling a special “Buyer Guide” form (it’s often called a Used Car Window Sticker) that discloses whether or not a warranty comes with the car. Many small lot car dealers don’t comply with the law. If they don’t, then you may end up with a warranty after all and you may even have the right to cancel the sale. The back side of the form has to be completely filled out and many car lots, big and small, fail to do that too and that can also trigger your right to cancel the deal. You can see what the Buyer Guide form looks like on this web site page: http://ohiolemonlaw.com/used-car-lemon-law.html . You need to talk to a local Consumer Law attorney who deals with this kind of case (it's called "autofraud" or car sales fraud) and find out what your state laws say. Call your local attorney's Bar Association and ask for a referral to a Consumer Law attorney near you or you can go to this web site page for a Free Online 50 State National List of Consumer Law Lawyers (http://www.ohiolemonlaw.com/ocll-site/ocll-locate_local.shtml) and find one near you (lawyers don’t pay to get listed here and most of them are members of the only national association for Consumer Law lawyers, NACA.net). But act quickly because for every legal right you have, there is only a limited amount of time to actually file a lawsuit in court or your rights expire (it's called the statute of limitations), so don't waste your time getting to a Consumer Law attorney and finding out what your rights are. If this answer was helpful, please check the box below.