public ArrayList<Car> findCarsById(int id)
    {
        ArrayList<Car> cars = new ArrayList<Car>();
        for (Racing temp:racing1)
        {
            if (temp.getId()==id) cars.add(temp);
        }
        for (Racing temp:racing2)
        {
            if (temp.getId()==id) cars.add(temp);
        }
        for (Truck temp:trucks1)
        {
            if (temp.getId()==id) cars.add(temp);
        }
        for (Passenger_car temp:passenger_car1)
        {
            if (temp.getId()==id) cars.add(temp);
        }
        return cars;
    }