Before the movie itself, there's a short. "Alphabet Antics" seems to have been made to be shown to young children at school, with a sweet-voiced narrator making up rhymes of a sort with at least tangential connections to a variety of sometimes bizarre bits of footage. As if in response to the apparent target audience, the "riffing" is full of barbs ("O is for the obscene treatment of animals." "T is for tortured, tormented, and tossed!" "X is for existential dilemma."), but it all seems to work together.
As for the movie, it starts with the truck-driving Phil Sandifer getting into a disagreement with the sports car-driving Jana Ryan that can only be settled by a night race with pizza at stake as soon as Phil has performed a musical number in a local "teen" hangout. (As with "The Giant Gila Monster" and "The Beatniks," the movie seems an attempt to build up a singer, in this case Dick Contino.) During the race, though, Phil's most morose friend Sonny DiMarco ("All I can think of is death; death, man!") manages to have a run-in with some ominous characters and then gets killed in a flaming car crash. ("Wait a minute--whoa--the cutaway caught fire!") Phil comes under suspicion and his driver's license is revoked; he suspects Jana for a while, and then they work out that the ominous characters were involved and Phil goes to work for the rotund Sidney Chillas (played by Bruno VeSota, who appeared in several other Mystery Science Theater movies) and his thuggish yet thick glasses-wearing henchman Bruce Green. As the riffing begins making "butter" references every time Sidney appears, Phil gets a fake driver's license and starts running dope up from Mexico, performs at Sidney's "teen" nightclub ("Why couldn't this guy be on the plane instead of Buddy Holly?"), and at last battles the bad guys to a standstill and gets his name more or less cleared. In a sort of "everybody has to start somewhere" note, the movie's jazzy soundtrack is by a young John Williams himself; there seems to be a dig or two at him in the riffing and the official Mystery Science Theater episode guide as well.
This movie was the first black-and-white 1950s American movie (following three "Film Ventures International" repackaging efforts and three dubbed Japanese movies) in the third season, and I do wonder if it's a little too diffuse for me to really think it outright "bad," not quite a "juvenile delinquent" caper. Still, there are some memorable "host segments," featuring Joel performing the "Pants Up Song," inspired both by the first number and Dick Contino's pants, Mike Nelson making a "Hexfield Viewscreen" appearance as Bruce, and the episode getting stretched out to running time when "the button" doesn't stay pushed at the end.