can anyone tell me what is the source for the awful smell?

Is it that urine smell? In my other cars, that was a sign of pooling water at the condenser drain eventually fermenting; however, this leads me to ask if you've changed your cabin air filter.

changed it when i purchased the car, which was last month. The smells comes and go away when ac is on.

you might have a dead animal stuck in your car somewhere.

just classic, eh.

I've seen times where rats would crawl up in the a/c vent intake ( behind the battery ) where the filter is, then make a nest. It makes for a disgusting urine/crap smell, not to mention the whole black plague thing...

its a common problem on every car, google it

any time you run your a/c about a couple of minutes before your destination, your supposed to turn off the a/c and run just regular air so that the lines aren't condenesed with moisture and then make a smell, my friends a mechanic and that s just what he says>????