It all unfolded on the streets of Santa Monica. To this day, it’s unclear who started it, though most people seem to think that Audi cast the first stone. BMW responded, and what unfolded next was one of the most famous advertising billboard spats that’s ever existed…

Here it is, in all it’s glory… The BMW vs Audi Billboard Ad War:

But of course, BMW are known for having this last word… Like with this tongue in cheek ad aimed directly at competitor Mercedes-Benz: