Well, I have to say that this community has never been so enthusiastic in my time in LFS.
I would conclude the following when thinking about lfs development: don't care about the new physics and cars so much. People desire new content. Release 2 new environments and 2 cars as S3 content and add more on both when you finish the additional environments. No matter if they are not perfect, they still are better than the old tracks. You can make them perfect later. And when people have gotten bored with the new content, release the tyre physics and everything is upside down - new challenge for everyone.