I would rather keep LFS the way it is and NOT allow modding. Allowing mods online are always a pain in the ass(talking about other games that allow mods); not everyone has the same mods. Like rigs of rods; theres SO many mods for that game its not even funny. You can use these mods online, but if someone else doesnt have the mod, or you don't have someone else's mod; you or they are invisible, then online is completely useless. Or Microsoft Flight Simulator; if you don't have the person's mod, you can still see them. It just substitutes the mod for something you already have, usually something not even close to the plane really is. I got really tired of it substituting ALL the planes I didn't have with only the aircraft carrier...
Its too late though, people have already made car mods for LFS. They're illegal to use, but people are using them anyway. If those mods were made legal, I would probably stop playing LFS. Im extremely picky about mods anyways; if I download a mod for any game, it has to at LEAST be as good quality as the game's original content... We don't need to ruin LFS with a bunch of low quality, junk mods...