Instructions
Play the game until all three cities are unlocked. There are a total of 36 Rockstar logos scattered throughout the three levels. Each stage contains 12 Rockstar logos to be found.
Go to the locations specified on the IGN "Midnight Club 3 Dub Edition" maps. The maps are taken directly from the game itself and the locations of all the Rockstar logos are clearly marked. Websites like Cheat Code Central has descriptions of all the Rockstar logo locations without a map for players that still want a challenge.
Drive over the Rockstar logos with your vehicle to collect them. For every 12 logos that are found, the player will be awarded with something new. The first 12 gives players a "Rockstar flag" style vinyl to customize their cars with. At 24 players are awarded with Rockstar license plates for their cars, and at 36 any of the race starters can be chosen as riders for the game's motorbikes.