I dont suppose there's a lot else you could paint on a large radiator without it looking demented
I read in a book that there was at least one pilot in the Great War who painted a face on his cowl flaps. I think he painted the Kaiser and the idea was to fly low over the trenches
and open and close the cowl flaps. This gave the effect of a cartoon as a different picture showed with the flaps open then when they were closed.
Does that make sense?