carbon guilt

resulting buyers remorse that ensues from purchasing a carbon fiber body part for an automobile that is expensive to the buyer, with the buyer soon realizing that said part has no effect on increasing performance /speed /power of said automobile.

guy1: I spent all my paycheck to install a carbon fiber hood, but i ain't seeing any difference.
guy1: Man ... i got serious carbon guilt.
guy2: Didn't I tell you to buy the Turbo Kit instead??? Dumb ass!!!