Dynamat 19405 18" x 32" x 0.067" Thick Self-Adhesive Sound Deadener with Xtreme Trunk Kit, (Set of 5) Dynamat Xtreme is coated with aluminum for high temperature areas such as firewalls and floors. Dynamat Xtreme is also recommended for trunk lids, roofs, quarter panels and under-hood installations. Apply Dynamat Xtreme to your vehicle's resonant surfaces and enjoy improved clarity, loudness and bass response from your car stereo.