To do this tutorial you must have a great understanding of the pen tool in ADOBE PHOTOSHOP, i will not go throu each individual stage and walk you throu every little thing i do, you will be left to your own devices, but will help you the best i can.

Open up the image you want to cartoon, create a new layer and label it "lines" now select the "pen tool" and start drawing around the car do little bits at a time, make sure you get every little detail. when you've finished you should have something like this.