When I lived in Wisconsin I had a (nutty) customer with a SAAB 900 Who would pull over on the side of the road if he hit 3k miles and change his oil. He also used airplane wax, said it gave him better gas mileage. However, the car turned 1 million miles and He donated it to a museum. SAAB ended up giving him a brand new 9-5
https://www.saabplanet.com/1989-saab...d-to-a-museum/