The kitten was tiny. We heard it meowing when we got the car home. This was pre-pandemic time with overcrowded lots. The car was at a "remote" lot, so we didn't get to see where it was parked. Our conclusion was that either the car was home to a litter of kittens or that the litter was closeby and the kitten just climbed into it. It was in the summer, so no need for it to be looking for somewhere warm. The kitten rode the 30 miles home from the dealership. We spent multiple hours during the evening trying to lure it out of the engine bay of the car, then decided best option was to drive back to the dealership the next day. Since we charged the car both ways, it never ran on gasoline so no hot or turning parts. All in all, one lucky kitten.
Reminds me of @K8QM's great post with a photo of a groundhog peering up from his Clarity's engine bay.