3ds Max Modeling :: Tweak / Remodel Existing Model?

I have recently purchased a 3d model of a car which I need to make 3d print ready for a project. I have come a long way since, getting to know the software and finishing all of the chassis. However, whilst editing parts of the car's bottom side, I noticed that when viewed from this perspective it is badly out of shape. When compared to a real model, one can see that the body is way too narrow in between the tires, making the whole thing kinda look like a bone. I have attached pictures of both, the unedited 3d model I purchased as well as a real model which I know to be very accurate to the real thing, to show you what I mean.