Advertising, just like tobacco smoke or vehicle emissions, one could claim is harmful to the consumer. Spam likely has deleterious effects upon cognitive health, thus the FIA might consider eliminating ads on the cars and on the tracks.
A side benefit would be an improvement to the aesthetics of the cars. The spectator would be able to view the car as a car, rather than a billboard. This would improved the spectator's experience, as they get to observe sculpture without distraction.
If museums are facing funding shortfalls, do they place stickers on the fine marble and bronze of their collection? Since the FIA is in the business of styling cars while making political statements, perhaps this is something they could consider.