TheStreet’s Jim Cramer is revved up over auto parts companies like AutoZone (AZO) and Genuine Parts (GPC), based on what he's seeing with their stock charts. ‘Autozone has the best buyback of any stock in the New York Stock Exchange,’ said Cramer. ‘All you have to do is look at the float and how much it’s shrunk.’ Cramer also noted that AutoZone recently reported slightly better than expected earnings. He added that Genuine Parts acts like it’s a take out, and O’Reilly Automotive (ORLY) has ‘just been consistently good.’ Cramer said these stocks are benefitting from the fact that the average age of a vehicle on the road is twelve years old. Cramer is portfolio manager of Action Alerts PLUS.