No way - used cars transacted between 2 private parties (non-dealers) are implied to be "As-Is" sales.
Without a legal contract it is "Buyer Beware" or "Sold as is".
Not if you sold it as-is.
You should have had the buyer sign an "Sold as is" document with or without refund, meaning that the car is being sold with possible needed repairs. This would be the same thing as autodealer ships use when selling previously owned vehicles. However, the decision is really up to you. What reason did the person give as to why he wants to return the vehicle? To avoid any conflict with the person, the right thing to do is possibly consider taking the car back and giving the person back their money. But again, that is your decision and you should explain that the car was being sold as is.
Buyer pays tax.
What do you mean smog a car? If car is sold "as is", buyer is responsible for all mandatory smog control equipment. If you mean pass a smog inspection, there are none in Iowa.
no because it is not new
The buyer does, seller can sell without registration on it, it is up to the new buyer if he/she wants to register it.
you have every right to denie him as long as you sold it "as is" and had him sign the paper saying it
Did you know the vehicle had problems when you sold it and if so did you tell the buyer? In a private sale the law says 'let the buyer be ware' but as a human being if you knew there was a problem with the vehicle and did not tell the buyer about it then you have been less than honest and should pay for the repair or take the car back and return the buyers money. If however you had no Idea there was a problem then (if the law in you country does say 'let the buyer be ware') the risk and bad luck is probably with the buyer.
maybe you mean reserved price at a car auction? The seller set the reserve price he wants to really sell his car. The Buyers bid on that car till they achieve that reserve price. If the Buyer doesn't achieve the reserve price the car is not sold. It will be sold only if the reserve price is reached or higher.
This situation depends on the state you live in and how long you have lived there. If the state has a buyer's remorse law, they may be able to return it. Most states do not have consumer protection for used cars and it is a no warranty situation as well as a buyer's beware situation.
NO. It can be sold any way the bank wants it to be sold