Round the Twist
(7 Network children's comedy series, 1989-2001)
Episode 1.08: Wunderpants:
In which Pete puts his underpants in the microwave to dry them and discovers that wearing them gives him super powers - which is how he's able to drag his school bus out of trouble with his bare hands. The bus in question is former Melbourne 531, a 1953 AEC Regal III with Martin and King body: