Forget about cleaning the car, I think he'd better work on his story - the paint spray pattern doesn't even support the excuse:
"I bought a spray paint and put it inside the car, but it somehow got caught under the seat. I didn't know so when I adjust the seat it punched a hole on the can and the paint blew out like a jet engine........"
Looks like it started spraying in his hands!
-- Tigger "It's not the years, it's the mileage" ~Indiana Jones