I believe that I have fixed this now, well a temporary fix. The water appears to be getting through a sealant that is sealing a gap more or less where the arrow is just below the bumper line. I think that the sealer is called Tiger seal or something. Anyway I do not have any of that so just had to use loads of silicone sealant as a temporary fix. I am guessing that this is not the best stuff to use and will eventually come off. So I will probably take the bumper of again in the near future and remove the silicone sealer and more of the tiger seal and re-seal it and then paint over it. Just thought I would post the findings just in-case anybody else has the same problem.