So Steve, as a Petaluma resident did you know that the first "day" of filming of American Grafitti was in San Jose, essentially from 9pm to 6am? They ran into camera mount difficulties, lost at least 1/2 day and then the next morning the city fathers told them that they were rejecting the contract and they were no longer welcome in San Jose. George Lucas went to Petaluma who opened their arms to the film crew, and the rest is history. They did use some cruise scenes from San Jose to broaden the cars seen, but not being familiar with the cities I have no idea which scenes might be San Jose vs Petaluma.