GTA:IV C# vehicle spawn example.

/// <summary>
/// Spawns a vehicle with a given name, a certain offset from the player.
/// </summary>
/// <param name="vehName">Name of the vehicle to spawn.</param>
/// <param name="offsetPos">The offset position from the player. (Positive X is right, positive Y is front, positive Z is top)</param>
/// <param name="headingOffset">The heading offset in degrees.</param>
/// <returns>0 on success, 1 on failed spawn.</returns>
        private int spawnVehExample(string vehName, Vector3 offsetPos, float headingOffset)
        {
            // Get the player heading.
            float vehHeading = Player.Character.Heading;

            // Offset the heading.
            vehHeading += headingOffset;

            // Get the spawn position.
            Vector3 vehPos = Player.Character.GetOffsetPosition(offsetPos);

            // Spawn the vehicle.
            GTA.Vehicle veh = World.CreateVehicle(vehName, vehPos);

            // Check if vehicle is spawned correctly.
            if (veh == null || !veh.Exists())
            {
                // Error code 1: failed to spawn vehicle!
                return 1;
            }

            // Set heading.
            veh.Heading = vehHeading;

            // Success
            return 0;
        }