“Cars 3” marks both a welcome return to form for a franchise that flew off the track with its international spy sequel and a puzzling progression for a series whose first and biggest fans are kids. A decade after a family road trip inspired John Lasseter’s warm, if familiar, tale about a cherry-red race car who learns the value of humility, hard work and friendship from the denizens of Radiator Springs, Lightning McQueen (Owen Wilson) wrestles with similar themes, though this time from the…