How come my scion tc's ac smells like dirty feet?

Answer 1

Could be just nasty air from outside traveling through your vents. Make sure that your car is recirculating the air inside your car rather than allowing air to come from outside through your vents. There is a button on your HVAC controls -- looks like an arrow pointing at the front of your car. Make sure its on. Hope that helps.

Answer 2

You have a mold buildup in your air conditioner/heater box. There are cleaners available that you simply spray into the fresh air intake for your cab. Check with your dealer - they may have a kit available.