After George McFly stands up to Biff and punches him for harassing Loraine, Biff now realizes he can no longer make George or anyone do his work, and he has to do things himself. Thanks to his aversion to filthy automobiles caused by twice running into a manure truck in his own car in 1955, he would come to the homes of his customers to wash and wax their automobiles. One of his customers was George McFly, who liked two coats of wax on his BMW 733i. The business phone number, listed on the side of his pale yellow truck, which appeared to be a Ford Courier, was 840-3851. Biff also had 'Biff's Auto Detailing' matchbooks printed to give to his customers and advertise the company; he was intending to show one of these to Marty McFly when he witnessed the flying DeLorean departing for 2015.
While Marty and Dr. Emmett Brown were in Hill Valley of 2015, an elderly Biff stole the DeLorean and went back to 1955 to give the Grays Sports Almanac to his younger self. Given how the book possessed all of the records of sports wins from the 1950s to 2000s, Biff bet on the results the book contained, and amassed a fortune. With this, the history of his auto detailing business was replaced with BiffCo Enterprises. When Marty destroyed the almanac in 1955, using a matchbook he had taken from Biff Tannen's Pleasure Paradise Casino & Hotel in 1985A, the text on the matchbook's cover changed before his eyes from PLEASURE PARADISE to AUTO DETAILING. In a kind of poetic justice, Marty had burned the almanac using a matchbook advertising the corporate empire that this very book had made possible.
It would appear that Biff still ran Biff's Auto Detailing in 2015, as he would wax (two coats, naturally) the hover-converted orange and black BMW 633CSi convertible owned by his grandson Griff. It is unknown if Biff was still running his Auto Detaling business because he fell on hard times which forced him to keep working, or he was just keeping active.
Behind the scenes
- Biff's yellow truck is never seen fully on-screen, so it remains unknown as to whether it was a Ford Courier, a Datsun or a similar vehicle.