Two theaters full of exhibs curious to see whether Pixar and Disney could extend their hit streak to a seventh film, got their first look at “Cars” Tuesday evening in the CGI toon’s first public screenings. Exhib reaction was generally positive — especially to the technical quality of the CGI animation — though some questioned whether its two-hour running time would cause tykes to squirm.“Cars” helmer and Pixar creative guru John Lasseter, on hand to introduce the pic, said the crew had just thrown their wrap party Saturday. Toon is about a cocky NASCAR racecar, Lightning McQueen (voiced by Owen Wilson), who ends up stranded in a small town on Route 66 on his way to the championship race in L.A. Two hours is on the longer end of the lengths of Pixar’s titles, but hardly unprecedented. “The Incredibles” ran 115 minutes, while “Finding Nemo” was 100 minutes. Older pics were generally closer to 90 minutes. Among the audience was Pixar competitor Jeffrey Katzenberg, who will unveil his company’s summer entrant “Over the Hedge” in a pair of screenings this morning.