Press "E" to Open material Dialog Box.
Check the box for primary texture and then click the "Load Map"
Your setting should look like this.
The result is HERE
 

Convert the Right view or UV Mapper..U will see the image you loaded.
OK.. Switch to Faces Mode by pressing 3 and select the faces as shown...

Now click on Surface> Mapping > Assign UV. Make sure that SEL button is pressed. Click on the car.

Now zoom out in UV Mapper and u will see a vertical bar near image.
Deselect SEL button. Press 4. Click Modify > Scale. Click "Y" on top.
 Click on the bar and drag it to shortn it. Do same by pressing X axis.

Now move this object to the grey suqare with surrounded black lining.
It should look like this.

 

Similarly create lining for the other parts like this. A little mapped car is HERE.

Complete the mapping in the directed way and the result is HERE.

Now its time to get the 2nd half of the car. Remember we will create the bottom after we have the complete exterior of the car.

Getting the 2nd Half of Car:

Now when we have completed the mapping we will create the 2nd half and the mapping will be there automatically.

Switch to Objects Level.
Click  Select > All and right click on the car. It will turn red.
Now click the Create > Objects > Copy and then click on the car.
A dialog box will appear asking u the name of new object. Name is Body 2. 
Click OK.

You will see a new object in the Objects Bar.
Hide the object Named Body by deselecting it.
Select X axis.
In menu bar click Modify > Mirror and click on Body 2. It will be mirrored.
After mirroring you will see the object like this.

Now select Reorient below Mirror and click on object. It will be normal again.
Now move the object o the next Quadr and unhide BODY.

Now we will weld the both parts.

Welding Both Parts:
In objects car right click on Body and click on SELECTED. like this.
. Do the same with body 2. Both of them will turn red.
Select Create > Objects > UniteSelect and simple click on the car.
A dialog box will appear. Your setting should meet this image.
. Click OK.
You will see that both objects disappeared and a new object :HB has appeared.
If this is it then u have done it correctly.
Ok. Now switch to Vertices level.
Select Select > Quadr.
Now in it apprpriate view select the two facing vertices on both halves and click on them. They will be united. See the image.
. The vertex after clicking will look like this.
. In the same way select each two facing vertices and unite them.
NOTE: Beware when u select vertices as any vertex behind that vertex will also be selected. So be very very careful and Accurate.

After uniting all vertices the car will look like this.
. The result is HERE.