This did not start happening until my a/c went out then I started noticing after if rained my passenger side mat was soaking wet. I put a towel in between the mat and the ground after it rained one day the towel was dripping wet and he top mat was soaked!
What is causing the leakage under my glove box to soak my front passenger mats? on 2004 Volkswagen Touareg
In mine it was a stopped up plug in the engine compartment. It was filled with debris and clogging the drain hole up. Allowed water to stay in the vehicles body and come inside where the cabin filter is located. It requires removing the front tires and splash guards. On the front of the firewall near the tranny hump is a rubber gasket with small hole in it. Pull the plug out and allow the water to drain and replace the plug. Don't park anywhere around trees thereafter.