I have the 2006 Mustang two-door with V6. There is no garage currently and I've noticed that although the window weatherstripping seems fine and the windows do seem to retract all the way up when the doors shut, if it's a windy/rainy storm I'll get wet carpets even if the car hasn't been driven ( not coming up through floorboard or down behind firewall ). I'm wondering if there is some aftermarket sealing trick or if I'm just going to have to put a weatherproof cover over the car?

 

your cowl drains are plugged and the cowl channel fills up with water and then spills in thru the cabin filter housing, thus resulting in the wet carpet and weird electrical issues as the SJB in the passenger side kick panel gets wet and the connections corrode over time. there are 2 cowl drains, the pass side is down between the battery and back of engine, you might be able to see it but for sure feel it if you get your had down there. its an oblong 3 or so inch rubber funnel type drain, just pull it out and clean it and reinstall. the drivers side is in the same relative area on opposite side. very common issue on the S197 cars and even had several TSB available to read. good luck

 

Look beside your battery against the firewall. Under the cowl you will see a "rubber thing". Like bl187 said. You may need to see it with a flash light. When you find it, just gently pull it out and clean it. Very easy fix.

 

I pulled those rubber drain plugs out of the firewall a long time ago when I was noticing the carpet at the passenger Foot area getting wet ....This most recent occurrence Was mainly on the floor behind the passenger seat nothing in the front seat floor area at all That's why I'm thinking that when the wind blows hard it's somehow getting around the windows... I just don't think this car was designed to sit outside of a garage in the winter If nothing else I'll put some kind of tarp over it

 

if thats the case, its your seals above the upper door trim. search my threads and go back a bit. i used truck bed camper seal to fix both sides for about 10$ and less than a casual days work.

 

Thanks, I'll search for that