With giggles over I've picked myself up off the floor--there's simply no direct way to reach that area. If you remove the entire heater matrix the air intake leaves a smallish hole for access under the "shelf" in the cowl. Water and other shmutz gets channeled to either side, down through a chamber on each side and winds up in the rocker boxes. If you lift off the plastic door sills you'll see plastic "plugs" in the inner rockers. Other trim can be removed to allow pulling the carpet back enough to use the openings in the inner rockers to vacuum, wipe, rinse, etc. whatever you find there. The pinch weld at the bottom of the rockers incorporate drains--make sure they're open. -- Dave