Hi, I may have an idea, although I am not sure how good results this may have:
In my opinion, one problem of this forum is the fact that it is a united forum for two different BMW models, E21 and E30.
I think that fans are interested mainly in threads about their own model.
As the thread titles are not always including the model's name (for example: a thread is not always: "Problems with E21" or "E30 with new suspension" or similar, but most of the times are like: "My car won't start in the morning" etc.), this makes search of interesting threads more difficult for somebody who is interested only in one of the two models.
At least that is the case with me. I have to open one threads to read what it's all about, and then just close it and go to the next, and this makes it difficult-just think the time it takes to close one and open another...