I would say that keep it as it is right now. Drag Racing Models section is the best section of this forum and it's easiest to find reference, or ask reference for Drag Racing Cars. Same thing with NASCAR, if there's only one General place where to ask reference, those topics can be easy to miss, since there are very much of them. I really like the way it is right now, but just point out, that Drag Racing Models need to be posted into Drag Racing Models section, and NASCAR models into NASCARS section. And those threads can be moved from Under Glass to right sections, if someone still doesn't understand and posts those still in Under Glass? Or is moving topics tricky?
I don't know which one I should vote, but this is my opinion.
If It Aint Broke, Don't Fix It.
EDIT: But if you're gonna do those changes, how about Large Scale Models in the Big Boys section, or Diecast Models? They have still own sections, just like Drag Cars and NASCARS. I think it's more simple when there are seperate Drag Racing and NASCAR sections.