Look at the dash board, see any spots that look like dead insects? Look a little closer these might be mice droppings. Also look on seats for same items. See any ripped up napkins? These are signs that mice are setting up house. These mice, 7 caught in traps so far, ate through the air intake filter and set up house. When brought to the dealer I found this problem was not covered by warranty. They refused to offer a fix. I don't know about you but if a mouse popped up thru the vents while I was driving--I might be so startled that I might drive off of the road.