Depends on the private seller.
Yes you can if you have the receit
After a car sale, a private party can return the car within thirty days. This return policy is dependent on the individual seller.
online, car dealership or a private seller!
No.... The time to check a car out is before you buy. Unless otherwise agreed to a purchase from a private seller is typically AS IS so buyer beware.
You cannot just return a car to the seller. There is no cooling off period on the sale of a vehicle. In your situation you can call the seller and ask for your money back, or ask the seller to repair the vehicle. If the seller refuses, your only recourse is to sue the seller in court. If you bought this car "AS IS" and there was no implied or written warranty then you will have to prove in court that the seller knew the engine was about to lock up. You must prove that the car was not serviceable on the day you bought it and the seller knew it. Get a written statement to that fact from 2 mechanics and that will strengthen your case. Otherwise you will probably loose on a car you bought "AS IS'.
Try to talk to them and see if you can work things out. If not take them to a small claims court.
If you are a GA resident, you do not have to pay sales tax as long is it is a private seller, even if out of state private seller.
Yes if the seller does not specifically state the car is being sold AS IS and it is not as discribed or advertised in a public listing such as penny savor, craigs list ect. the buyer has the right for a full refund within 30 days of purchase.
Only if the seller expressly told you that it did not have a rebuilt title. That would be fraud. Otherwise, it was incumbent upon you to know the history of the car before purchase; while the seller should have disclosed that information, he wasn't legally obligated to do so.
Not unless the seller expressly stated something that turned out no to be true. For instance, if you asked the seller whether the transmission was good and he verbally guaranteed it, and you then found out it wasn't, you have recourse to ask for your money back. However, there's no 3-day return rule for vehicles, new or used. You struck a contract with the seller when you bought the car and it belongs to you.