Carlos reviews Extreme Online Store's carbon fiber rear diffuser for the C8 Corvette Stingray in a YouTube video. Priced at $1,399, the full carbon fiber piece features a unique Herringbone pattern in the middle, matching Carlos's rear wing. He recommends ceramic coating to prevent yellowing due to heat exposure. The installation process is detailed, highlighting challenges, such as a difficult-to-reach bolt, making an electric wrench advisable. The fitment required some persuasion, and Carlos had to use M8 bolts for the mesh grill, but overall, he is pleased with the appearance and recommends the product.