Here's where practical reality vs. ego inflation kicks in.
An aluminum bodied speedster will, side by side, 'look exactly' like a fiberglass speedster...indistinquishable... and, depending on invisible mechanics, will perform exactly the same...whereas a unique vehicle such as an American Roadster or a Gmund replica will stand out in crowd screaming "Hey, look at me!!"
After all, isn't THAT EXACTLY what this madness is all about?