Auto is neuter and it does not chage in the accusative case: https://cs.wiktionary.org/wiki/auto#podstatn%C3%A9_jm%C3%A9no
Isn't it the same?
To wait on smth seems to be some Souther U.S. regionalism. You must forgive us if we don't know that in Europe. It is not that clear it should be accepted as standard English, but we probably will but it will take time to spread into more questions. You must count that it won't be accepted in many cases.
"wait on" is a malapropism. It means "to serve someone, " as in "the waitress waits on the customers". In the US it now means "wait for" According to this article wait on has a different meaning than wait for. http://www.grammarerrors.com/grammar/wait-onwait-for/