My Car is Making a “Clanky” noise

We had a customer come in with a nasty odor in her car. We thought there might be a dead mouse in the heater box. Take out the blower motor and cage for a look see. Nope all good in there. It smelled dead for sure but seemed to go away when the blower was on. Guess what we found in the trunk? A rotten pound package of hamburger in the trunk down at the quarter panel. Mo Fo that was some nasty stuff!!!!!!
The gal had gone to the butcher shop a week earlier for some meat and one fell out of the basket.