During the city chase, Roddy notices a floating balloon and tells Rita to head for it. Roddy grabs the rope pulls the balloon towards a tunnel blocking it from the Toad's thugs. True, it gets burst seconds later, but the fact that it was the naive Roddy, rather than the street-wise Rita, who came up with the plan, shows awesome Character Development on his part.
While this troper generally disliked the film, respect is due for this exchange on a speeding boat:
Spike: Any last requests?
Roddy (knowing the baddie has a spring attached to his back and anchored elsewhere): Yes - could you fly off quite suddenly in the other direction, screaming like a girl?
After Roddy manages to get back home, he finally manages to grow a spine, and lets Sid know he has had ENOUGH.