my suggestions: i know its not finished but i would use areas of tone instead of the hard lines
also, to create depth with tone, the areas closest to you will have the greatest range (black to white) where as the areas farther away will have less range (dark grey to light grey)
First of all great job man! The drawing and obvious skill are both impressive.
(I have a BS degree in fine arts...)
If it were my drawing I would add some shadows to the underside of the fenderwells by the tires and try some various shading techniques on the windows. The sketch loses a bit of the sense of volume the rest of the car has because the windows appear flat. You might try some light areas of shading with a very hard lead and just experiment.
Actually I was thinking more like a 2-4H (harder lead), the regular #2 is still pretty soft. Who knows till you try it though I guess....sweet drawing though man!