Cousins rarely, if ever, look alike. As the family tree branches out, relatives grow farther and farther apart from their genetic starting point, which Charles Darwin would point out is necessary for a species to adapt and thrive.
The Aventador and the Dreamliner rely heavily on carbon fiber and carbon composite construction to create a structure that is both strong and light, aiding in both performance and (in the case of the Dreamliner) fuel-efficiency. Both offer up cutting-edge design and construction techniques, too, paving the way for future generations of product.
If you think the Aventador - Dreamliner pairing is odd, consider this: forged carbon composites developed jointly between Callaway Golf and Lamborghini have found their way into both supercars and golf clubs. While a Boeing and Lamborghini family reunion would be odd, we suppose inviting the Callaway side of the family would prove to be stranger still.