Here's another idea..

In World War II, the British built a plane called the Wooden Wonder, this was the fastest prop-powered plane of WWII. And it was made from plywood.

Hermann Goering, the Reichsmarschall and head of the German Luftwaffe, was quoted thus:

"In 1940 I could at least fly as far as Glasgow in most of my aircraft, but not now! It makes me furious when I see the Mosquito. I turn green and yellow with envy.

The British, who can afford aluminium better than we can, knock together a beautiful wooden aircraft that every piano factory over there is building, and they give it a speed which they have now increased yet again. What do you make of that?"

The infamous East German Trabant car had a body made of paper laminate.

So why not make the body panels out of wood or paper? that would allow for more creativity and more curvy shapes. Without the expense of fiberglass.