"and spray the cover with cats propellant"
Black powder, gasoline, lighter fluid - any of these would make a good propellant. Then all you need is a confined space to act as a barrel, and voila, airborne cat. Problem solved.
I'd go with the cover.
Not on this car, but I have had cats that would crawl up in the warm engine compartment to sleep (Older american cars that USED to have enough room around the engine to actually reach things). The bottom ground effect panels should prevent that on the Box.