Unlike his father Sparkplug, Buster Witwicky doesn't understand cars -- or for that matter, anything mechanical. Buster prefers reading books, much to the frustration of his father. If only Buster were interested in something useful, like auto repair. Instead, foolish Buster, if he keeps on reading, may end up with a paid scholarship to college. That is a road that could only lead to ruin.
He has an older brother, Spike, who is away at college.
(Note: Buster and Spike, as well as Butch, were all names considered for the Witwicky boy character in early production material. For some reason the Cartoon ended up going with Spike as his name and the Marvel Comic material with Buster. "Butch" was even used in one coloring book. For much of the Comic's run they were basically the equvalent of the same character. It was only when Fortress Maximus' toy was released with Spike as it's Headmaster partner that, to accomodate this, Sparkplug gained an older son and Buster a brother, bringing a seperate Spike into the comic and transforming the two from equivalent counterparts to definitively seperate characters.)
Marvel Comics Continuity
Buster and his girlfriend Jesse are making out at a drive-in theatre (blocking the movie from view of his friend "O") when their car is hit from behind by a yellow Volkswagen Beetle. Buster gets out to investigate and discovers that the little car is unmanned. There's no one inside! Suddenly, the drive-in theatre becomes a war zone as jets appear and attack. During an explosion, the Beetle is damaged. Buster is stunned to realize the car seems to be crying, and leaking a strange substance which is not oil! Buster sends his friends to get help, while he drives the Beetle home. His father can fix it.
His father, Sparkplug, is overjoyed at first when he stumbles across Buster and the Beetle in his garage. Has his son decided to follow in his foosteps? But before Buster can explain, the damaged Volkswagen Beetle speaks to them. "Help me, please! I'm dying!"
Following his father's death, Buster racked up enormous gambling debts, which Spike ended up having to pay off. Buster subsequently joined the military.