This test was not intended to precede a "Gran Turismo 4 Online" full scale release but instead to be used as a way to develop and test online features and structures for the upcoming "Gran Turismo 5" on the PlayStation 3 system. Besides the 5,000 test players, seven special guests were invited to test "Gran Turismo 4 Online". First, a special event named "Top Racer Battle" (トップレーサーBATTLE) was staged in the Polyphony Digital headquarters on August 17. Six drivers from the JGTC Japanese championship entered the game's online multiplayer "Competition" mode.