Man, you guys really have money to burn...I would NOT put the SB in the engine bay at all without sealing it inside a water-proof box. Something clear would look real nice, but not exposed to the elements like you guys are doing. Maybe I'm just more careful here in Washington State because it rains 80% of the time. At the least, I would not put it under the battery box ventillation tube without blocking it off like others stated, but block it off up inside the hood scoop to ensure you dont get any water dripping on it. Also, what about water coming into the engine bay from the front of the car?
Be careful!