Step One

Collecting and Calibrating BPs Of Car:

There are usually four views of a car we use... 

1. Front
2. Rear
3. Side
4. Top

but the top view may not be present. The front and rear views should have a length and width of 512 x 512 and side and top view of 1204 x 512. 

Here I will use Honda Civic Sedan to create. You can use these images as blueprints. save them and I tell you how to use them as background.

Images have been scaled down to fit the screen.

Remember We Create Car's Half and the other half is done as we copy and flip it....

Adding to Zmodeler:

Now open Zmodeler and load these images into their appropriate views like this

it will look like this. In right box you will browse the viewport, named "right"

in the same way load images of top and front. We will use rear image when we create rear side.

Creating the Flat Surface:

Now we create flat surface of the car. You can see different words on the right side of Zmodeler like Create Modify Surface Select Display.

1. Click on Create and in the popup menu click on Surface and again in popup menu click on FLAT. Create > Surface > Flat.
2. Then click and drag the mouse from front wheel to rear wheel and then left it. you will see a menu. Name it BODY and keep Horizontal Steps to 0 and Vertical Steps to 5. If You will see something like this then you did it correctly.

NOTE:   Use "+" and "-" keys on Numpad to zoom in and out.
    

Now click on Vertices  or simply press "1" and then click on flat surface you just created. You will see some red dots.

Click on Modify > Move. Make sure that SEL at the bottom of menu is not pressed.

Now click on "Z"  and move vertices number 2 of top by click and dragging on the red spot up to the start or door. It should look like this if u did it correctly.

Now click Create > Faces > Strip  and click on vertices no 1 and make vertices around the wheel like this.

similarly make vertices around the rear wheel. The result is HERE. Now we will create the whole side just like we created the rounds for wheels. It should look like this.

 The result is HERE.

Ok now here our Creation of Flat surface is finished. Now will convert this flat surface to the 3D surface or mesh.
NOTE: Keep looking in the 3d view and make your vertical vertices on right angle. and horizontal ones on 0 angle.

PROCEED TO STEP 2................