GTA 5: Get free SeatIndex

int GET_FREE_SEAT(int VehicleHandle)
{
    int numSeats = GET_VEHICLE_MAX_NUMBER_OF_PASSENGERS(VehicleHandle);
    int SeatIndex = -1;  //Driver seat = -1
    while (SeatIndex < numSeats)
    {
        if (IS_VEHICLE_SEAT_FREE(VehicleHandle, SeatIndex))
            return SeatIndex;
        SeatIndex++;
    }
    return -2;
}