Of course, I accidentally closed the browser after writing a long message for you.
Febreeze makes a good product for cars, but it's best when you've completely removed the stain first.
My best advice would be to make a paste out of either baking soda/water or Borax/water (saw this on the Borax box last night to neutralize pet urine odors) and vacuum once dry.
Our daughter's sippy cup fell out of her seat and landed upside down last year without our knowledge. After a few days, we smelled the sour milk and found the cup. The thing that worked best for us was to get a car carpet cleaning solution (any auto section) and clean what we could, then take a towel folded a few times, put it on the area and apply some kind of weight to literally wick the remaining vomit out of the upholstery.
We learned this from the Queen of Clean's website (she had been on Oprah many years ago and swears she hasn't met a stain she can't get out) because of our dog constantly throwing up bile on our carpets (works like a charm). http://queenofclean.com/
Good luck!