Here's a quick video of a matchup between the BMW M3 ESS and the Audi RS6. Regardless of the winner, each car will still have its share of loyal fans who'll continue to claim their car is better.
The Matchup - Evotech of Germany's white Audi RS6 vs. ESS of Arizona's red BMW M3 (E92). The Audi has Quattro all-wheel-drive and a ~750hp. The BMW has a ~720hp but weighs less than the Audi.