I'm also on the Miata.net board and they have many of the same divisions/sections you do here for suspension, tires, electronics, etc.

One neat thing they have next to the thread title is a little selectable icon to mark if the topic refers to the NA, NB, or NC generation of Miata. It completely depends on the poster selecting it of course, but this kind of thing here may make separating GD vs. GE stuff easier when new GE people are searching and reading before posting redundant questions or remarks.

I see you already have the same standard icons, you just need to add a GD and GE radio button.