Try entering one of the locked boroughs early to get an immediate six star wanted level by taking a car on the subway tracks. Start picking off cops one by one to raise your wanted level. After you get a four star wanted level, go in your car and drive into the subway tunnel. Once you leave the flashing wanted circle and your wanted level disappears, the achievement will be yours.
Simply enter the restricted area in the airport and use your driving skills to evade the police.
Get in a taxi as a passenger, set a far away waypoint, and tell him to drive there. Enable the "Add one star to Niko's wanted level" code and repeat until you have a four star wanted level. Skip the taxi ride to your destination. When you get out you will lose your wanted level and unlock the achievement.
Go to Francis International Airport and steal an Annihilator helicopter, but make sure that you have the four start wanted level from entering the restricted area. Fly at least as high as the Empire State Building over the city. Note: The game will not allow you escape the police while in the stolen helicopter. When you are going fast enough and very high, jump from the helicopter and land in a body of water. You should move so fast that you leave the "circle" behind, but you won't die because you landed in the water.