ARRAYLIST_ERROR

package montederamosarraylist;
import java.util.*;
import java.util.Scanner;

public class MontederamosArrayList {
private static ArrayList <Vehicle> car = new ArrayList<>();
private static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        
        while(true){
            System.out.println("1 - ADD/REGISTER VEHICLE");
            System.out.println("2 - DISPLAY DISPLAY VEHICLE");
            System.out.println("3 - REMOVE VEHICLE");
            System.out.print("Choice: ");
            int choice = Integer.parseInt(sc.nextLine());
 
            switch (choice){
                case 1:
                    addVehicle();
                    break;
                case 2:
                    displayVehicle();
                    break;
                case 3:
                    removeVehicle();
                    break;
        }
    }
    
}
public static void addVehicle(){
        System.out.print("Enter plate number: ");
        String vehicleNumber = sc.nextLine();
        System.out.print("Enter vehicle owner: ");
        String vehicleOwner = sc.nextLine();
        System.out.print("Enter vehicle model: ");
        String vehicleModel = sc.nextLine();
        System.out.print("Enter vehicle year: ");
        String vehicleYear = sc.nextLine();
 
        Vehicle vehicle = new Vehicle(vehicleNumber, vehicleOwner, vehicleModel, vehicleYear);
        vehicle.add(new Vehicle(vehicleNumber, vehicleOwner, vehicleModel, vehicleYear));
        System.out.println("Vehicle has been added!");
    }
    public static void displayVehicle(){
        System.out.println("All Registered Vehicles:");
        for(Vehicle vehicle : car)
        {
            System.out.println(car);
        }
        //for (int i = 0; i < car.size(); i++){
            //Vehicle vehicle = car.get(i);
            //System.out.println(vehicle.getVehicleNumber() + "-" + vehicle.getVehicleOwner() + ", " + vehicle.getVehicleModel() + vehicle.getVehicleYear());
        }
    }
//both display and remove is WRONG!
public static void removeVehicle() {
    System.out.println("Enter plate number to remove: ");
    
    for (int i = 0; i < car.size(); i++) {
        if (car.get(i).getVehicleNumber().equals(vehicleNumber)) {
            car.remove(i);
            System.out.println("Vehicle " + vehicleNumber + " has been removed.");
            return;
        }
    }
}
}
class Vehicle{
    private String vehicleNumber;
    private String vehicleOwner;
    private String vehicleModel;
    private String vehicleYear;
 
    public Vehicle(String vehicleNumber, String vehicleOwner, String vehicleModel, String vehicleYear){
        this.vehicleNumber = vehicleNumber;
        this.vehicleOwner = vehicleOwner;
        this.vehicleModel = vehicleModel;
        this.vehicleYear = vehicleYear;
    }
    public String getVehicleNumber(){
        return vehicleNumber;
    }
    public String getVehicleOwner(){
        return vehicleOwner;
    }
    public String getVehicleModel(){
        return vehicleModel;
    }
    public String getVehicleYear(){
        return vehicleYear;
    }
    @Override
    public String toString(){
        return vehicleNumber + "-" + vehicleOwner + ", " + vehicleModel + vehicleYear;
    }

    void add(Vehicle vehicle) {
       
    }
}