Thanks for the replies. Cabin filter changed 3 years ago and six months ago. Air filter six months ago. No debris or objects observed. Car has never been driven or out in the rain or wet roads. Never trash or eating in the car. Odor has been present since bought with 47 miles on the odometer when bought from Hendrick Cadillac, where it was kept in the showroom. Will look under seats and rear this morning.