Hey guys, when I was washing my Jeep after the 101 I saw a round area that had water in it directly under my fuses(?) and air box. I thought that water just collected there when I washed it. I checked again today closer and saw that it is a reservoir of some sort and the round area looks like a cap could screw on top but I couldn't get a good enough look to see if it was threaded. So being the curious cat that I am I stuck my hand in the hole and sure enough it is a hole filled with water. What the he'll is this thing? Oh I guess I should mention that this is a 2011 JK. Please forgive me for being a noob if this is a simple question.