After I took our '04 V6 Touareg (18K miles) through a high-water-pressure brushless car wash, we found the front passenger-side floorboard water soaked. The I-love-anything-German mechanic who services my '88 Porsche 911 was out of town repairing a state ferry engine and another VW-specialist garage said we don't do water leaks, take it to a body shop. Body shop said this is Alaska, we don't do water leaks in winter (Huh?). I thought it might be a windshield seal, so I took the Touareg to a bright, conscientious young guy at Speedy Glass who previously charged me only $6 to perfectly cut a piece of mirror glass to replace a broken mirror from an outside rear view mirror ($200+) on the 911. He suspected a plugged drain at the bottom of the fire wall but a visual check was blocked. He removed the entire windshield wiper assembly so he could also access and remove the plastic cladding across the bottom of the windshield. Eureka! Now he could see down into bottom behind the engine. A drain hole at the bottom of the fire wall was plugged with sucked in leaves. He used a vacuum to suck out the leaves and crud and a couple gallons of water poured out. Per a previous website tip here, he also checked the sunroof drains but they were fine. And Speedy Glass/Juneau now has a chap named Doug who actually knows how to carefully remove and adjust those mad-scientist windshield wipers.
Cheers,
jholbert (Josef)
Juneau, Alaska