This is what I did.
I went to the Garage and then My Cars and pressed the Y button to filter and selected Cult Classics. I picked the 1973 Nissan Skyline with a B class setup. Anything below A class will do.
Then I went to the menu and to the Social tab, and clicked 'Online Adventure'. Now I chose 'Custom Adventure', and 'Games Only'. Now you can choose the class, I picked 'Always B'.
Not many people play below A class, in my case just one. Second place guaranteed. I played a game of Infected, let myself get infected and the challenge was completed, three wheelspins awarded.