Question about Wheels champions

[lentinant]

I have cleared all locations that I can access except last one, and final Wheels champion who asks me to defeat other champions. But there are literally no other champions left. Is this something I will be able to do only in post-game?

[Koby]

It can be done before post game. The Wheel Champ won't play you until you've beaten everyone else which includes buying a wheel table and taking it to the place that doesn't have one so that you can beat them.

[Metal Hero Regulus]

While sailing, hold L1/left bumper (or whatever the keyboard bind is) to set up camp, and there's a Wheels Champion on the boat.

[lentinant]

Messaggio originale di Koby:

It can be done before post game. The Wheel Champ won't play you until you've beaten everyone else which includes buying a wheel table and taking it to the place that doesn't have one so that you can beat them.

I know. But I also have parrot, and if there is location where I haven't beaten champion yet, parrot says so. ALL of my locations are clear, other than fish-shaped island that I was unable to access until the very end, and location of actual final champion. So, unless there are two champions on Mesa Island, I don't know where could be champion I'm missing. I also have 5 wheels (from bronze to diamond) and 6 hero figures (pretty much every single one I've seen with other contestants).

[lentinant]

Messaggio originale di Metal Hero Regulus:

While sailing, hold L1/left bumper (or whatever the keyboard bind is) to set up camp, and there's a Wheels Champion on the boat.

Oh, this might be the one I'm missing, thank you.
Those things you need to do some optional action to get into hidden location, are rather confusing.