class Car {
  color c;
  float x;
  float y;
  float v;
  
  Car(color colour, float xPos, float yPos, float velocity) {
    c = colour;
    x = xPos;
    y = yPos;
    v = velocity;
  }
  
  void move(){
    x=x+v;
    if (x>width){
      x = 0;
    }
  }
  
  void display(){
    fill(c);
    rect(x,y,50,20);
  }
}

Car myCar1;
Car myCar2;
int redness = 0;
int greeness = 255;

void setup(){
  size(400,400);
  myCar1= new Car(color(0,255,0),0,300,0);
  myCar2= new Car(color(255,255,0),50,200,10);
}
void draw(){
  background(0);
  myCar1.move();
  myCar1.display();
  myCar2.move();
  myCar2.display();
}
void mousePressed(){
  myCar1.v=myCar1.v+1;
  redness=redness+10;
  greeness=greeness-10;
  myCar1.c=color(redness,greeness,0);
}