I did this achievement with the Arcade Mode.
I used a Sprint race in the US.
10 Rounds are round about 13% on my progress.
So I did the following settings:
East Mitten Sprint
I am not sure, but I need round about 30-35 min for 1 race.
I used a rubber band and touched somtimes the right stick, to not disconnect with the controller :D
Hope it helps.