All VRML files start with a header that identifies the version/information encoding scheme. Here the ASCII format is being used. A VRML browser will reject any VRML file that does not contain this as its first line. The pound symbol (#) indicates the presence of a comment - information useful to humans, but thrown away by the computer. The computer ignores text that follows the pound sign until the end of the line - the exception to this is the header line.

#VRML V1.0 ascii
We will specify the whole world as one object. This will allow us to use this world as a component of a larger world. Separator is used as an object wrapper.
DEF World Separator {
The whole world rotated 30 degrees on the x-axis.
   Transform {
      rotation 1 0 0 0.52359878
   }
Directional Light is put in front of the car. It is not enclosed in a Separator because it is supposed to illuminate all the objects within this world.
   DirectionalLight {
      on        TRUE
      intensity 1
      color 1 1 1
      direction 1 0 0
   }
The definition of the object car starts here.

   DEF Car Separator {
The left front wheel is defined here. The transform node is enclosed within an object, so it only affects the children objects. Material node is used to define the color of the wheel.
      
      DEF LeftFrontWheel Separator {
         Transform {
            translation -2.0 0 2 
         }

         Material {
            diffuseColor 1.0 0 0
         }

         DEF Wheel Sphere {
            radius 0.9
         }
      }
Similarly, the right front wheel is defined. However, the actual definition of the wheel is done by aliasing the previously defined object, Wheel. The Wheel object replaced the three commented lines. This can reduce the size of the VRML file.
The keyword, DEF, gives a name to an object node, and the definition of the object can be referenced later by this name. The name need not be unique. If multiple definitions use the same name, then the name refers to the last definition just before the use of the name.
      DEF RightFrontWheel Separator {
         Transform {
            translation -2.0 0 -2 
         }

         Material {
            diffuseColor 1 0 0 
         }

         USE Wheel
#        Sphere {
#           radius 0.9
#        }
      }

      DEF LeftRearWheel Separator {
         Transform {
            translation 2.0 0 2 
         }

         Material {
            diffuseColor 1 0 0 
         }

         USE Wheel
#        Sphere {
#           radius 0.9
#        }
      }

      DEF RightRearWheel Separator {
         Transform {
            translation 2.0 0 -2 
         }

         Material {
            diffuseColor 1 0 0
         }

         USE Wheel
#        Sphere {
#           radius 0.9
#        }
      }
The body of the car is defined here. Cube shape node is used for constructing the body of the car.
      DEF Body Separator {
         Material {
            diffuseColor 0 0 1.0 
            shininess 0.2       
         }
         Cube {
            width 6
            height 1
            depth 2
         }
      }
   }
}