hey man. you REALLY improved!! im glad to see you did that well on the first try, there is actually perspective going on there, rather than the all-out crookiness of your past works. evem the wheels look better. I agree, tough, that your shading is quite bad. its a difficult part to achieve on a drawing, and I suggest you keep practicing and look at many, MANY car photos to see how light reflects and how it looks in the metal. and two things about designing:
one: this has to do with your shading, precisely. if you are gonna design something, find a car that looks similar to your design and look at how the reflections work on the car, then try to achieve something similar in your car, with gradations and full-on white and black surfaces. that is, until you get the feeling on how metal surfaces look and how to achieve the gradations without looking at a photo... its just experience and practice. but EVEN then, looking at a photo helps a lot 👍
two: you just cant do a car and pretend is a Jag, a Mitsu, or whatever, each company has its image, its distinctive lines and characteristics. if you are gonna make a jag, try to make it look like a jag, Ferrari... you get the picture. if you dont want to, just make the design on yourself and call it yours. the fact that yer car looks nothing like a jag or whatever you say it is takes away a lot of credibility. if you instead say "its a mine

" the results will be better (:
Cano
keep practicing man, you have improved a LOT. nice.