Forget the floors and carpet - if the cowl drains plug, water backs up and flows thru the blower, then thru the heater core and evaporator - then trickles down on the amp for the audio system.



So, no, you don't want water backing up in the climate control system. But honestly, I have no idea where that drain is - but I think it's in the passenger side front wheel well - or darn close to it. Get the car on a lift or ramps and find it! I just don't know if you can 'snake' it and clean it or not.