I know about Gjed, that's a shame, it was killed when they moved the default build to dx11. I think it still works downloading an old buld of the game, but then the user has to update his mod to dx11. Right now though there is also Blender (the gmt exporter-importer plugin works with the 2.79 version and the author is working on the 2.8 version). I started playing with the conversion of the RF1 content for RF2 just few weeks ago and 3dsimed isn't so easy and fast. Still, I think that the fact that they are improving the look of the game and introducing a customizable interface can convince more people to mod for it. How can I say? Better than nothing. Two days ago I have installed the Virtual_LM GTPC mod for RF1 and the custom UI is awesome (not to say the content). I don't think I've ever seen a custom UI in RF2, just plugins for the hud and custom showroom backgrounds. If I remember well RF1 and GTR2 didn't have specific tools for modding, beside the documentation and the help provided by the devs. The tracks were done with BTB, 3dsimed and Max and many cars were ripped from other games (just like today), or made from scratch using Max. RF2 has documentation and tools about the physics elements, but they are difficult to use. I think that they are aimed to people who already know how to do things. What I would like is an updated Gjed for the graphic stuff and a simple tool that allows the user to create the engine-tire-suspension-gen-spinner-hdv files with few clicks and providing few data about the car. Right now it's not so easy, peope just borrow these files form other cars most of the time. But you never know,since they said that they are planning to update their old content to the new tech, maybe they have an updated version of the Gjed and they will release it to public. I hope so. Now that Kunos can't officially support the modding of ACC, the modders will encounter similar difficulties for that game.