Jay Leno spoke to The Post about his all-thing-cars show, “Jay Leno’s Garage,” back for its third season Wednesday (9 p.m.) on CNBC. This season’s guests include Gabriel Iglesias, Wanda Sykes, Brad Garrett, Josh Duhamel, JB Smoove and Ted Koppel. Ted Koppel? Is he a car guy? Ted had one of the first NSX’s, so...