Try replacing the the gasket between the windshield frame and tub. I had to silicone mine because of rust on the windshield frame.
There are a couple, they are under the carpet, there are 2 rubber seals in the front (one on the passenger and driver side) and a couple where the "bed" or trunk is There are a couple, they are under the carpet, there are 2 rubber seals in the front (one on the passenger and driver side) and a couple where the "bed" or trunk is
The usual cause is a bad seal around the windshield or body rust under the seal. The windshield needs to come out and bodywork done or the seal replaced.
If your vehicle has a sunroof, the drain tube may have popped out of it's outlet. This tube runs down inside the roof support on the passenger side of the windshield, running down just in front of the passenger door behind some plastic. I have a 2003 XRS. It had a really musty smell that we traced to the front passenger side carpet. When I pulled the carpet back, it was dripping wet. The air conditioner drain hose had pulled away from the firewall and was draining into the floor pan. I replaced the tube into the hole and have not had any trouble since.
It sounds like their house could use a renovation. Replacing the carpet and repainting the walls would be a good way to freshen up the space and give it a new look. This could increase the aesthetic appeal and potentially even the value of the property.
I hasd a similar problem with a 1990 Camaro. My carpet was wet from a leaking heater core. Smell the carpet where it is wet. Does it smell like antifreeze or is it the color of antifreeze? If so nyou have a bad or leaking heater core. Good Luck
On the 2011 model, it's on the trunk under the carpet
Typically the front passenger side floor/carpet gets soaked with engine coolant and when you turn on the defroster, the inside of the windshield fogs up.
Moldy carpet should not be cleaned, it should be replaced. Consider that by the time the carpet has molded, the padding and underlayment have already been damaged and need to be replaced or repaired.
You probably have a bad heater core. Find where it is coming from. You probably have debris stopping up the drain below the windshield.
Some carpet can be repaired easier than others. Most can have a section replaced if you have some of the same carpet or perhaps a piece could be taken from a closet or from under a piece of furniture.
it is under the carpet on the passenger side,
Just to the passenger side of the spare tire under the carpet.Just to the passenger side of the spare tire under the carpet.