How to build your RoadArt Masterpiece
Take the VW (left), tip it on it's side and cut this (right) from it. Trim cone (like the barrel pic below)  Be sure to save the
torsion bar, tranny and engine, if it's good.
                                   
Trim, wire brush (or sandblast ) to remove old rust and scum from it and prime it
                                           
and you should end up with...
this!
Fabricating the Twin Beam Components
CARDBOARD TWIN-BEAM PATTERN
I suggest making a cardboard frame first. It is not only considerably cheaper,  but you can use   it as  a pattern
when it is completed, and simply trace it to  your
steel beams after you are satisfied with it. Use 2" strips
for the upper Twin-beam,  and 3" strips for your
lower Twin-beam components.

 The actual length of the frame components WHEN COMPLETED are: 'A' 39". 'B' 23", 'C' 21", and 'D' 32 1/2".
                     
Begin by cutting a strip of cardboard 3" X 63" for the Lower-beam     components.
Then cut a piece of cardboard 2" X 54" long for the upper beam components.
                                   
The actual cut on the 3" beam is 315 degrees from TDC (top dead center).   The actual cut  on the 2" beam  is 290 degrees.
However, there is an easier  way for most of you to make a pattern.
                       
To make frame components 'A' & 'B', measure 39 1/4" from the edge of the  lower beam.  Next run  a perfectly
square vertical line from top to bottom of     the 3"
strip. Next measure back from the top of that line      2 1/4", and   draw another  vertical line  top to  bottom.
Now connect the two lines with a     diagonal line,
starting from the top of the rear line and finishing at the    bottom of the first line.  That should put you
in the ball park
To make frame components 'C' and 'D' , follow the procedure above, only  make the first line 21"  from the edge  of the
2" strip, and measure back    11/16" for the second line.
Connect them diagonally and you should have    your upper
beam angle. The finished beam components should measure:
 A=39X3", B=23X3", C=21X2", and D=32 1/2" or close to that. A little bit  off doesn't matter much.   I've yet to make  two  perfectly
identical frames.