This is a parody of the flashes "Sonic Stereo" by BigNasty4Life and "Sonic Uncut 3" by HyperactiveYouth. It's Sonic versus Shadow rivalry, but not in the form you'd expect. :) The flash will repeat itself after the final song ends, so be sure to close the window before that point if you don't want to watch it again.
Just so you know, this takes place in America, but they're riding in a British car (inside joke). That's why Shadow appears to be driving on the wrong side of the road :)