Microsoft Flight Simulator has World Hub and X-Plane has Scenery Gateway. Where the community can use a predefined library of buildings and 3d objects to improve airport models in-game, like terminals, ramps, taxiway and runway markings etc, while its still WIP, the idea is to let community vote on these submissions and then push the higly upvoted improvements into the base game. Because all the 3d objects are predefined, it doesn’t require new assets to be added with each update and it keeps the “bloat” to a minimum/zero.
Imagine having something similar for FH6 (or maybe the next installment). Having a library of 3d objects & shapes, kinda like livery editor but for 3d objects, and let people make splitter, rear wing, side skirts, exausts, body parts/kit etc for each car, let the community vote for it and then bring these body parts into the base game.