Do the extrusions shown to shape the rear area of the car. Make sure that the vertices as the center of the car have and x-coordinate of zero.
Now back to the front of the car. Select the headlight polys and delete them. Select the edges around the headlight and extrude them inwards a little.
Select the edges shown and then click the little button next to the chamfer button. The "Chamfer Edges" dialog box will pop up. Change the chamfer amount to a small amount, I used 0.15 and that worked well in this case. Chamfering the edges serves to make the edges sharper when the car has been smoothed. If you smooth the car now, you will see that there is now a sharper edge around the headlight region but you will also notice that it's not perfect. This is because the chamfer operation created some extra vertices that are not needed. We are going to have to what I like to refer to as "Vertex Cleanup."
Zoom into part of the headlight as shown and you will notice that there is a triangle of vertces. There need not be 3 vertices there but only 2 so we need to weld two of them together. Target weld vertex 2 to onto vertex 1 and then do the same for the vertices in the remaining red squares. Now when you smooth it, it should smooth perfectly.
Now we need to begin dealing with the hood. Make the cut shown in red
Now select all the polygons that make up the hood and click the "Detach" button. When the little window comes up, name it "Hood" then click ok. The hood now becomes its own object, independent from the rest of the car.