Agree with Dzurinko and Retiredguy123. I’ve sold numerous vehicles over the years. Simple Bill of Sale - I list my name and address (as on the title), buyers name and address. Description of the vehicle, including Serial Number, date of sale and Signature lines with date for you both to sign. Take two copies (originals) - sign both; buyer signs both - give him one and you keep the other one. Remove the plates and return them to DMV. Cancel you insurance on the date following the date of sale/transfer.
You can find sample “free” Bill of Sale” examples on the internet.

In most states, used car sales are understood to be "as is." This means the buyer understands that if something goes wrong after the car is driven away, it's entirely his or her responsibility. That means that, as a seller, you're not responsible for the car after it's sold. Just make sure they sign the check or agreed signature or the purchase 😉

I have a fun anecdote. I sold a car to a relative, signed the title and they drove away. 11 months later, they had only made one payment when the sheriff showed up at my door telling me the car had been used in a drug deal and confiscated (boyfriend). I ultimately had to get the car out of impound, pay towing fees, and a ticket. None of that was legally required, but I took great pleasure in selling the good car to a friend in need for all those costs. Settle your deal at the DMV.