The Paradise City police vehicles in "Burnout Paradise" contain sirens with two different sounds. The siren is available on two speeds on the Hunter Calvary, Hunter Mesquite, Krieger Pioneer, Nakamura Ikusa GT, Hunter Manhattan and Carson Fastback. The Xbox 360, PS3 and PC versions require a different method to use the siren. However, only one button function is needed in any version.
Press the "L3" button on the PS3 version to use the siren. Hold the same button to use the second siren.
Press the left analogue stick on the Xbox 360 version. Hold it for the other siren.
Press the "P" button on a keyboard for the PC version. Press and hold the button down for the additional siren.