MY OOP PROJECT

Hi there, I am really glad to be a student in this extraordinary course.
When it comes to my project, I am studying OOP at my university and I needed a course that is perfect and teaches me OOP, and I found you :)
Despite the fact that you teach it in SC, I was able to convert everything into Java for my studies.
here is my full code :
public class TheProject {public static void main (String[]args){
Car car1 = new Car("Red","Toyota");
SaloonCar saloonCar1 = new SaloonCar(2);
SaloonCar saloonCar2 = new SaloonCar(3,"Nisson");
SaloonCar saloonCar3 = new SaloonCar(4,"Ford","Purple");
}
}
class Car {
public String color ;
public String manufacturer ;
public Car(String _color , String manufacturer){
this.color = _color;
this.manufacturer = manufacturer;
}
}
class SaloonCar extends Car{
public int numberOfSeats;
public SaloonCar (int _numberOfSeats ){
super("Unknown","Unknown");
this.numberOfSeats = _numberOfSeats ;
}
public SaloonCar (int _numberOfSeats ,String manufacturer ){
super("Unknown",manufacturer);
numberOfSeats = _numberOfSeats ;
}
public SaloonCar (int _numberOfSeats ,String _color , String manufacturer){
super(_color , manufacturer);
this.numberOfSeats = _numberOfSeats;
}
}