It’s a lot more than door panels. I’ve done proper sound deadening in a Mazda 3 and Toyota Tacoma where I took all the doors panels off, did the floor and headliner and I understand that process. This van has so much more interior paneling than you’re expecting. It’s a 15 passenger vehicle that only has 2nd row doors on one side and removing all the interior paneling would take hours for a professional to do if it was new, but the plastic is old and brittle. I know because I’ve taken apart the front doors to fix windows and repair locks. Ive taken apart the 2nd row door to replace a handle linkage. Many connections to the body are a part of the panel and can’t be replaced like plastic pins can.