When Mr. Broflovski buys a Hybrid car and becomes somewhat pompus, he moves his family to San Francisco, a City where everybody loves the smell of their own farts, to be away from the unenlightened people of South Park. To get his friend, Kyle, back to South Park, Stan goes on a campaign to get everyone driving Hybrid cars also. To do so, he writes a song ("Come on people know, people who need people now, come on people now, come on people now, drive a hybrid people now, everybody needs people now, people now, people now...") that becomes an instant hit. Everybody starts becoming enlightened and driving Hybrid cars.
The only catch: the smug levels in the city of South Park are rising and expanding, and soon will clash with the smug emissions from San Fran.... to make matters worse, George Clooney's Acadamy Awards Acceptance Speech is making its way from Hollywood...