Judging from the frame work/ wireframe/ poly flow, you use too much polies relevant to the amount of
detail
I guess you have over 2.5K of polies but it lacks abit of detail if you intended a wrecked car. It's a nice modeling job though, creating cars in MED isn't that easy
Btw, could you give us some more screens since my assumption about the amount detail can be 'wrong' due to the perspective angle through which you made those images.
Thanks in progress
Frazzle