One day, Lani accidentally breaks the car wash. Afraid she'll get scolded, she keeps it a secret. Meanwhile, Rogi declares he'll find the culprit who broke the car wash and, acting like a detective, starts asking the little buses a lot of questions. Lani can't answer Rogi's questions straight away and gets suspected of being the culprit. But with Tayo's help, she is able to leave the garage safe and sound. Seeing Tayo do that, Rogi starts to think Tayo is the culprit. Rogi's preposterous investigation now begins.