Here are six common bad odors in cars, how to recognize them, and how to fix them.
How to Remove the Musty Smell from Your Car's Air Conditioning | Consumer Reports
Some people describe this scent as a syrupy smell, while others say it is sweet or a mix of bitter and sweet.
The usual culprit is a leaking heater core. Antifreeze has a sweet smell and when it leaks into the heater box, that sweet smell spreads throughout your car.
The windows also fog up with this problem. When the antifreeze evaporates and then condenses on the windshield, it creates a sticky film that is difficult to clean.