Lots of stuff going on here! This Yukon Denali is customized to the max. With 9 Video screens, its not your average grocery getter. Not only is this Denali a feast for your eyes, its also music for your ears. The entire cargo area houses four 12" Kicker Solo-Baric L7 subs. The L7's are a patented square subwoofer,supplying the extra decibels needed for deep, musical bass in a mobile audio system. Traffic Jamz also added four JL Audio 6.5" speakers to the rear pillars. We constructed a form to house the speakers and fiberglassed the enclosure. A white vinyl cover was applied to the fiberglass enclosure to match the rest of the interior. This Denali is amazingly loud!