The problem is that several people have been telling you that your ISO has been toooo high even I have at least once or twice before . It looks like this was at max ISO . The grain is so bad that it makes the whole picture a bunch of grain to look at . The point of practice and showing your work here is to heed what people are suggesting your picture could have easily been a Photograph . If you have a cheap tripod I would highly suggest you get a nicer one there are tripods with a total height before camera of about 1618 in which would fit under a semi trailer easily . You have all the opportunities in the world to shoot these awesome cars yet its wasted on these pictures instead of making art in photography .