Good advice; I recently sold a full size Chevy just by posting a photograph on a supermarket bulletin board. The car had dark red metallic paint which show really well. I cleaned the Michelin tires, shampoed the interior, changed the oil and put all maintenance and repair bills neatly in a binder. I had two roof racks which did not fit my new car, so I threw these in for nothing. Total preparation cost was about $40 plus some elbow grease.
The guy who bought it really appreciated this, and bought the car without even driving it. I got $100 less than I asked. Where I live we don’t need a fitness/emission certificate.
When you sell a car, it has to run smoothly, start easily and their should be no vibration in the wheels on a test drive.
People who don’t do any of the above always have trouble selling their cars.