I noticed that on the underside of the roof spoiler(if thats what you would call it), there is a hole. At first I thought I would look in and find a windshield washer fluid nozzle for the back window, but there appears to be nothing in the hole. I then thought maybe it is a drain, but being that it is curved, I would expect it to be center bottom. Can someone tell me what this hole is for...I am wondering if I am missing something.