[NaS]

Use a Timer..

Код:

//OnGameModeInit:

SetTimer("RotateVehicle", 1000, 1);

// e.g. bottom of your script:

forward RotateVehicle();
public RotateVehicle()
{
new Float:angle;
GetVehicleZAngle(vehicleid, angle);
SetVehicleZAngle(vehicleid, angle + 5.0); // Turn vehicleid by 5 degrees
}

The vehicle ("vehicleid" has to be replaced by your ID) will now turn by 5 degrees every second.