Now we are going to detail the inside of the front area. Select the green polys and extrude them to create the thin line of polys shown in red.
Select the edges shown in green and click the little button next to the "Connect" button. When the "Connect Edges" dialog box comes up, put in a value of 2 for the "Connect Edge Segments" then click "OK." This cuts the selected edges and inserts two edges going through
Select the thin row of polys formed by the connect operation and move them down in the z-direction just a little to give a small curve to the surface when smoothed.
Select the innermost edges (in green) around the hood area and extrude them downwards just a little to give a nice lip to the geometry.
Create a new plane and convert it to a poly object. Place it just behind the lip of the hood area and then do a series of extrudes from the back of the hood to the front to begin the inner walls of the hood area.
Now it's just a matter of sculpting the inside of the hood. Make the extrusions shown in red. There is going to be a spare tire near the front of the car so there has to be a depression for it and that's why I have made the front of the hood area curve downwards. You might want to create a cylonder approximately the size of the tire and place it in there to model the hood area to fit right or you can skip ahead to the tire creation part of the tutorial to make a tire that you can use here.