According to Life 123, a receipt for a car is also known as a bill of sale. It represents a binding agreement between the buyer and seller for the sale of a vehicle. Because of this, you need to get a car sale receipt in writing. You must take care to include all the necessary information about the buyer, seller and the vehicle itself when you prepare the document.
Include identifying information about the car. The North America Military Financial Education Center says this should include the make, model, year and body style of the vehicle. It should also include the Vehicle Information Number.
Check the odometer and include an accurate reading at the time of the sale. If the odometer shows an incorrect number, NAMFEC says the receipt should include an explanation.
Write down the selling price of the car and any promises or guarantees. Used car sales in most states are considered "as is" unless there is a written agreement to the contrary. Any guarantees made by the seller should be clearly spelt out on the receipt. Otherwise the buyer cannot enforce them if there is a dispute later.
List the name of both the buyer and seller and the date of the transaction and have both parties sign it. Each person should read the receipt carefully to make sure it is accurate, then print his name, sign it and date it.
NAMFEC says you can have the car receipt notarised as an extra layer of protection. Both the buyer and seller will have to appear in front of the notary and sign in her presence. Life 123 says you may be able to download a sample bill of sale for a car from your state's Department of Motor Vehicles website.