air outlet trunk vent issue.
 

Hi guys/girls. Im new here. Just picked up a 02 honda civic coupe. I replaced the trunk air vent since it was leaking... So today i look in the trunk and there is water again. I know its only that spot because i did the whole water test. When i pour water on the left rear side it goes over the fender and into the space between and goes into the top of the trunk air vent. I can physically see it leaking into the trunk from the top of the vent.. Im going to remove the bumper and put some rtv over the outside of the trunk vent also going to put some rtv between the spot of the fender also... What can i use to put over cover up the trunk vent from the outside?? it also seems to be coming in from the darn flap opening. is there anything i can put over the outside of it when i take the bumper off. some kind of foam sealant from home depot to put into and fill the whole flap opening up??? thanks guys/girls