There are five licenses available in Gran Turismo 4. Acquisition of each license is progressively more difficult to achieve than the last. Each license enables the player to enter more difficult events in career mode. Driving Missions become available when the iB license is passed, with later missions unlocked at iA level. The Licenses are (in increasing level of difficulty): * B License * A License * iB License * iA License * S License Subsequent prize cars are awarded when all tests are passed to silver and gold levels.