I realized about the defroster vents blowing right on either side of it, but I'm being careful about how much heat I'm throwing up on the windsheild. As for sun, might become an issue in the summer, but it's too dang cold here to worry about it right now. Plus I'm running a hard top right now which has made my rig a little more difficult to break into. I throw a ball cap over it whenever I park somewhere I'm not sure about... I just really like how well I can hear it mounted up there, plus I don't hit it with my head or knees!
My windsheild was cracked like that when I got the trucklet. My mechanic passed it because the crack wasn't in my line of sight(I'm 6'5", so the crack only cuts across my view of the hood!).