Another car rental story from your pal mmntech. When I first started working as a driver/cleaner, we had this old gentleman who came in semi-regularly. This man (white guy) stunk so bad, I can't even describe it. I've honestly never smelt anything like it before, but it was disgusting. Like he had never, ever showered once in his life. His odor was so potent, it would seep into the fabric and vents of the car. We couldn't rent it for at least a full day after he returned it. Just had to dump a ton of fabric refresher in it, then let it air out overnight.
I have never before or since encountered another human being that smelt that bad. Though I did work with this Indian lady that had such rank breath that the phone at work stunk days after she would go on vacation. She's still a distant second. She was such a nice lady though, we didn't have the heart to tell her.