2017 Dodge Grand Caravan - I believe we've had this noise for quite some time, every once & a while but lately it's been a lot more often. Any clue on what it is? It happens while driving or stopped. It also happens when the heat/AC is off. Lately (as it's gotten a bit warmer it seems) it's doing it much more often. Other owners tell me not to worry and it happens on theirs too, but I'm looking for more confirmation and an idea of what it is!