Yes, I did and it wasn't pleasant. I finally found that the car had a leak around the seal of the front windshield, and it was dripping down into the front passenger compartment. The floor was soggy when I found it and I'd been looking for the problem for a while. The carpet had mold and mildew under it on the padding and that was the smell. I had to take the carpet out, let it dry and shampoo it, replace the padding and wash the carpet. I let it all dry and then reinstalled the carpet. I had to seal the windshield too. It was a mess.
Don't forget to check under the hood and in the trunk. I've had food fall out of the bags taking it home from the store and get hidden behind the jack or my toolbox. Not always nasty but when it turns out to be meat or something like that, it can get really gross and it will permeate the car.