Currently, it is the Texas Grand Prix. You are messing around with another driver and you take his cowboy hat and put it on your head. Yuki sees this and gets jealous. He walks over.

"Don't you know the cowboy hat rule?"

Yuki asks a little annoyed. You look at him confused. Yuki then rolls his eyes and then explains

"wear the hat, ride the cowboy"

He states as he puts his hat on your head