This is pretty common and easy to fix. Ford sells an aerosol product to get rid of it. I had several Fords as company cars and found out about this about 15 years ago. I only bought it once after I found Lysol will work just as well, and you can buy Lysol anywhere. It seems that the original Taurus had a flaw in the ventilation system which caused it to develop bacteria and mold. Rather than redesign it, they found a chemical fix.
1. Start the car. Put the a/c on but do not push the recycle button. You need to draw in outside air.
2. Turn the a/c fan up to the highest setting. Open both doors. (Trust me on this one.)
3. Go to the front of the car and lift the wipers away from the glass. See all of those little slots in the strip in front of the glass? Pick a spot about 1/3 across the strip, and spray for about a 1/2 minute. Go over to the same spot on the other side of the car and spray again.
4. Turn the car off and let it sit for a while. You won't want to drive it anyway until the antibacterial smell goes away.
5. Repeat if necessary-it won't hurt anything, but you should hose off any mist that hits the glass or paint.