I'd make the roof panel less thick and chamfer/bevel the A and D pillars, and make B and C pillars thinner. Also, it looks like that some edges are not co-planar at all which you should fix, since it looks ugly.The fender looks awkward, you should probably make the full fender first and then add the bulge for the chrome strip. There might be more things, but that's all I could think of right now.I noticed that you simply stick deformed primitives together. It's not very clean.-snip-
I'd make the roof panel less thick and chamfer/bevel the A and D pillars, and make B and C pillars thinner. Also, it looks like that some edges are not co-planar at all which you should fix, since it looks ugly.The fender looks awkward, you should probably make the full fender first and then add the bulge for the chrome strip. There might be more things, but that's all I could think of right now.I noticed that you simply stick deformed primitives together. It's not very clean.