Start small, remember, it’s like an RPG, you don’t go fight Sephiroth level 99 at the beginning of FF7, you fight level 1 enemies cuz you are level 1 too.
What I think of as the third tutorial is REV, linking up https://cgcookie.com/courses/rev-model-a-low-poly-muscle-car
Learning 3D is not a race, no need to hurry. Try making the car following the tutorial. If you find it easy, then good, we know you are more leveled up than that. Then try making a low poly car on your own, see how that goes.
