Well, ehm, it's a bit boxy, but as Bjollets said, everyone must start somewhere, and in my opinion, the first few models are just for learning the program you are using
I can give you a tip though:
If you want to model modern concept cars, study the newest concepts and get some inspiration. However, don't get too "over-inspired", after all, it should be your
own concept you're designing
Oh, and by the way, I think it's gonna be pretty hard to see anything in those side-mirrors, they look quite small
As for the renders, i can say that your paint material is way too reflective, which makes it look awfully bright because of your white background.
What program did you model it in and what program did you render it in?