So I parked my car at my buddies house so I could ride my bike around all day since it was a nice day out. When I got back to my car it smelled terrible so I check to see if my son may have left anything in the back seat. While checking the floor I notice that the carpets were soaked in the back and in the front. I took the mats out and realized it was only on the passenger side. Half of the car was parked on the grass and it had rained the night before so it was very wet. Is it possible that being parked on the grass could do this. I tried vacuuming the water out but it is still wet. I didn't leave any windows open and he doors were completely shut. Any thoughts?

 

Is it possible someone spilled a water bottle under the passenger seat and "forgot" to tell you? Your car should be weather proof, so parking anywhere should have no effect. What about your door seals? Are they intact and in line? Did it rain on the car?

 

Try using a heavy duty shop vac and leave the doors open or windows down if the weather is nice.. dont want it getting mildewy

 

Had you left your car out in that rain the night before? I had wet in the footwell from the moon-roof drain hose coming adrift. Pour some water in the drain hole and make sure it doesn't come in through the lining of the front pillar. Just a thought.

 

Maybe your AC drain hose is clogged which could be causing a backup of condensation into the cabin.