This may have been posted already, as I haven't read the whole thread.
But does anyone remember the VERY politically incorrect one,

"The Esso sign means happy motoring (X3)
Call at the Esso sign!"
which was repeated by various oval-shaped Esso signs representing various races. eg a Chinese one with pigtails singing "Velly happy motoling" and an African one "De Esso sign mean..." etc.

As children we used to sing along with all the racist accents, even pulling our eyes into slits for the Chinese one. (1950's) Oh dear!