Oh, almost forgot. This is about airport loaner cars.
I guess it's safe to say most, if not all of them have some strange bumps, grinds and noises. I wasn't surprised then, when I took a loaner into town to get dinner that it had some thumps and bangs that I could feel right up through the seat. I just ignored them. When I got back to the hangar, I got my stuff from the back seat and spotted something under the driver's seat:

It's a coconut wrapped in plastic. God only knows how long it had been rolling around down there. Did I eat it? No, I put it back under the seat and pushed some rags into place so it's hiding place would remain secret and the next pilot could enjoy the full loaner car experience too.