var x = 0;
var y = 40;
var diameter = 68;
var speed = 10;

// loop forever
var draw = function() {
    // get rid of streaks/draw background
    background(98, 181, 245);
    
    // move the car
    x = x + speed;
    y = y - 0;
    
    // if the car is off the screen,
    // then put it back on the screen
    if(x > 300) {
        x = -400;
    }
    
    // car body
    rect(119 + x, 148 + y, 209, 100);
    
    // wheels
    ellipse(165 + x, 259 + y, diameter, diameter);
    ellipse(286 + x, 259 + y, diameter, diameter);
};