Years ago, I pulled into the driveway after a 15 mile highway trip (including speeds up to 80 mph), and turned the car (1980 BMW 320i) off.
Heard a strange, low-pitched groaning noise from the engine compartment.
Thought, gee, that's odd, the car is not even on!
Opened the hood with some trepidation to find . . . a cat in the engine compartment!
I guess he had crawled up in there and fallen asleep! Luckily, he was resting in a place that was on the intake side, so it was relatively cool, and towards the rear of the engine compartment, away from the fan and belts! He also had the sense to not come down while I was on the highway! He was a little shaken (duh!), and a little warm, but alive and well.
I didn't have any need for a cat, so I sent him to the good people at bonsaikitten.com!
(Ok, the last sentence is not true!! But the rest is!).