So Mini challenged Porsche to a race at Road Atlanta as a publicity stunt. Porsche corporate declined because they don't do publicity stunts.
Mini provided a Porsche for challenge. It turns out it wasn't really Road Atlanta, just a teeny go-cart track designed to give Mini an unfair advantage. It didn't really help.
I never really understood the challenge. Porsches and Minis already share real racing tracks all the time. They're just in different classes.
Perhaps Mini (BMW) should actually build something that could really rival a Porsche (something fast).