We had a "kitty accident" in our van on the way home from the vet :( Unfortunately, we didn't realize at the time that he had peed; we thought the odor was a "cat fart" according to our daughter. Consequently, we did not treat the area until long after it had dried. We've tried using vinegar and also a pet odor enzyme formula to remove the odor, but the results have been unsuccessful. Help! Thank you.