Lightweight design and noise reduction remain central challenges in modern automotive engineering, particularly with the growing adoption of electric vehicles where cabin acoustics directly affect passenger comfort. This study compares the acoustic behavior and sustainability profiles of conventional polyurethane (PU) foam-based headliners and Hanwha’s SuperLite thermoplastic composite systems. Standardized acoustic measurements were performed in an alpha cabin to evaluate absorption coefficients over the 400–10,000 Hz range. Results indicate that while conventional composites achieve strong performance in the low-to-mid frequency bands, SuperLite XL4 outperforms at higher frequencies, offering up to 20% higher absorption at 10 kHz. The thinner XL-TB variant, though limited in absorption, demonstrates advantages in weight reduction and material efficiency. From a sustainability perspective, both SuperLite grades provide benefits through recyclability and reduced material usage. Overall, XL4 presents the most balanced option, combining high-frequency acoustic gains with improved environmental performance, positioning it as shows potential as an alternative for next-generation automotive interior applications.