On 12/1/17, I purchased a 2018 CR-V EX-L which my wife and I thoroughly enjoy. One curiosity question: going into the garage late one evening, I heard a humming noise coming from the area between the two rear wheels. It sounded like a small fan running. Was not very loud at all. Started the car and backed it out of the garage and then drove it back into the garage and shut off the engine. Noise went away. I thought it might be a fluke. HoweverI have now heard it three time, always at night, because that is the only time it is quite enough to hear this humming. Do not know if it happens during the day because of other routine noises around. Stopped by local Honda dealer service department and asked if any of the technicians had any idea. Only idea that came up was maybe it was an emission self test/check. Has anyone else ever heard of something like this?