I share your concern. The best I can advice I can offer is get a repair shop to check it out when you smell the problem, you have to be able to duplicate the problem or they will not know where to begin. It could be as simple as some piece of plastic road debris that yo have picked up while driving or a valve cover gasket leaking onto the exhaust system. At this stage if it were electrical I would suspect you would have noticed blown fuses or things that no longer work. Your vehicle is too new to have serious problems but have you any coolant loss, possible heater core issues, perhaps spray Lysol aerosol disinfectant in the air vents/ ducts let sit for ten minutes the run heater fan on high, check cabin air filter. Last 3 ideas are just grasping at strays without being able to smell the smell first hand.