Fireman Sam (BBC children's series, 1987-91)

Episode 3.05: Trevor's Bus Boot Sale
A particularly taut episode of this animated show for preschool children involves the dumping of toxic waste and Trevor the bus driver being overcome by fumes. The bus is a Ford Transit, registration BWS493T, and remarkably well reproduced under the circumstances. Ewood Eddie notes "It carries a livery similar to that carried by National Welsh minibuses." .
Fortunately everything ends well:
The fire tender is quite good, too: