I unlocked this close to the end of my SECOND season, as the progress moves rather slow the higher up you get.
It's just one of those achievements that i don't think is a way to unlock it other than natural progress.
I also don't believe race distance or AI difficulty affects this progress, but please comment if you experience differently.
There are also Activites that can give some Acclaim, so watch out for them.
Just practice, qualify, and race :)