After posting on your page, I removed the spoiler and drained it. I then found four washers and applied a thin bead of putty on one side and placed them putty side down on the deck lid over the screw holes. This created a very small gap, which is barely noticable but it allows the water to drain out really quick. I hope this solves the problem.
P.S. I have your car on my screen saver. It was copied off of RKSport's site. Great job!
Do you have any problems with water being drawn into the RKSport spoiler and then slowly leaking out over the next week? This happens to mine and the worst part is that it leasves a stain that can only be removed with a carnuba type of liquid car wax.