We will start by adding a racetrack to the Stage backdrops. This way, we have some guidelines for the rest of our program. We know how the road is shaped and where the curves, corners, and walls are.
For the background, we will use an original Mario Kart map. You can find game images such as these all over the Internet. What's important to remember here is that the image you choose should fit your game screen. In this case, the game screen is 480 pixels wide and 360 pixels high, so a background image should be at least that size.
Another thing to note is that although these images may be freely available, it doesn't mean that they are completely free. The original artists put time and effort in creating them. Also the game studio and/or producer (Nintendo, in this case) invested money to promote and sell their game.