Gran Turismo 4 Prologue (グランツーリスモ4 プロローグ Guran Tsūrisumo Fō Purorōgu) is a racing video game that was not released in the North American market. This short version title preceded the release of the full-length version Gran Turismo 4 in 2004 and was followed by Gran Turismo 5 Prologue in 2007. Though it was necessary to limit the number of cars and courses included, this product still included some of the main features of the Gran Turismo franchise such as races, time attack and license tests. The sneak preview also expressed the latest technology Polyphony Digital had accumulated over the past two years. Featuring 50 of GT4's then-planned 500 cars as well as five courses, this expanded demo was designed as a stop-gap until the complete version was released. The game includes a Driving School (License Tests), Free Run and Time Attack as well as early version of some circuits, like the New York track which was modified in the full version. A new Gran Turismo official steering wheel, the Driving Force Pro known as GT Force Pro in Japan and supporting force feedback, was released by Logitech (Logicool in Japan) to coincide with the Gran Turismo 4 Prologue launch date. The European version came with an extra car not included in the Japanese version; the BMW Concept M5. Source: Wikipedia, "Gran Turismo 4 Prologue", available under the CC-BY-SA License.