Get the water out first, then if its definately the grommit try to move it a little to see if you can get it spot on not to let anything in, Id put sealant around it to be safe, so you dont rust from the inside out.Have you checked its not your lights letting rain water in ?, my ZS was check the foam gasket is there and doing its job, either get a new one or sealant jobby.Hope this helps.