I know that I would be a distant future, but I'm gonna just suggest this idea.
After seeing SkyTrack I just instantly thought about tools for creating own tracks. I mean it would be really hard for someone to create something like Industrial, but SkyTrack similar tracks shouldn't be that hard to do. I think.
Same about custom cars, UIs and paint jobs. I know that it's easy for me to say, because I wouldn't do anything from this but modders these days are creating true wonders
At some point maybe you should consider introducing Steam Workshop or something like that.
As I said, it's just a suggestion and I know that firstly game must develop more and community must grow.
Keep the good work