Be careful if you snake it because it's thin rubber tubing and you will rip it. The grill is nothing more then a gutter,rubber tube to the outside. You should be able to find it with a helper,hose and flashlight.:thumbsup:
If you have a coupe the vent will drain on top of the rear wheels if you have a convertable the vent drains through the rear compartment wall. If your vent and drain system is not damaged than most likely the drain tubes are clogged with tree debris. You can remove the drain caps and carefully clean out the drain tubes. If the caps are rusted through you can replace them with stainless steel caps. Coupe and convertable caps are different, make sure you get the correct ones.