I used rubber/cork gasket material and water proof sealant. Cut the size patches you want out of the roll of gasket material and use a hole punch for the stud holes (size of punch doesn't matter, the studs will go through the hole easily, tighter the better). Coat the underside of the patch with sealant and let it cure for 15 or 20 minutes before reinstalling the spoiler. Piece of cake AND 100% water proof.