Now that it has been brought up, I remember I also tried this. We have a fake plastic owl that we bought to put next to the bird feeder to “hopefully” scare off the squirrels, and it did absolutely no good… I do not believe it scared off anything. Small birds landed on its head and left their “calling cards…” The squirrels just seemed to ignore it… But we did try the owl around the cars, in front, in back, on the sides, even on the roof. It did not fit in the engine compartment and we continued to get the critter visits… And it was not like the engines were warm and the warmth was what attracted them. I have four vehicles and I rotate driving them, some of these vehicles might not be driven for 3 to 5 days apart, Only the 2019 Toyota and the 2020 Honda were parked outside, and I checked the engines of both every day. By the way, both cars are Silver in color. The '85 Toyota and the '01 Ram are parked in the garage.
I also have a very realistic plastic/rubber snake that I bought to put on top of the porch lights. Small birds (sparrows, wrens, etc…) have tried to make nests on top of the lights, I do not want the mess on the walls, railings, or benches on the porch, so I have put the snake up on the lamps, and like the owl, the birds ignore it. I ultimately put a plastic bag over the lamp during breeding season. They do not like the bag…
If Tropical Storm Elsa was not dumping rain on us right now, I would have included a “Family Portrait” of the Owl and Snake…