Hey girlfriend, I feel your anguish! The way I cope with hand cutting hundreds of tiny pieces for the cards I make, is to break the job down into small parts. I then reward myself when each part is finished.
Are the cars different colors? Can you cut out all the red cars then do something else? Go back in a bit and cut all the blue ones then take another break. Bite sized pieces are much easier to chew and you'll be all done before you realize what happened!! I know you can do this and it will be a grand quilt when you're done. ;)