Farmers around here have been pumping used auto tranny fluid into the body
panels of their cars for years... drilling holes when they have to and using
pump oil cans and brushing  or spraying on where they can... the machines
look pretty funky after a few years... but after a few years without oil
there  is no machine to look funky... the oil  works and will migrate quite
a way up hill ... I cannot imagine getting paint to stick to the surface..
even if you clean it with acetone and alcohol