General Motors and Chevrolet have pretty much made a living out of throwing stones at the competition (Literally) over their use of aluminum in truck beds. Ford's decision to use the lightweight material in the beds of F150's gave a huge boost to gas mileage by cutting weight, but truck tradition opened them up to ridicule for using something other than steel.
https://www.youtube.com/watch?time_continue=1&v=MnZFX3HyJ28
The joke is on Chevy, though, because now they knew they can't go with aluminum on their own truck beds without getting shamed into oblivion by the internet. So what is Chevy and GM to do?
They backed themselves into a corner, they know they need lighter weight trucks, but can't use aluminum. Instead, they will use carbon fiber in select trims according to the Wall Street Journal.
The super strong, lightweight material, once reserved for supercars only, would help them meet fuel mileage standards while still maintaining strength. Not to mention save face after their all out war on aluminum.
Related: Aluminum is old news for Ford; now they are looking to use wood to build cars