You can make your own WHAT THE CAR? levels using the Level Creator. Your levels can be as tricky, weird, and wacky as you want them to be. 

You can find the Level Creator in the Community Area (the right-most door in the home room). From there, you can use the Level Creator computer to make a level for any of the controllers that you have unlocked. If you want to unlock more controllers for the Level Creator, you have to beat a level with that controller in the episodes. After doing that, the controller becomes available in the Level Creator. 

When you've made your level, remember to name it and publish it so others can play it, too!