Suggestion from a very long-time forum user and admin, but n00b Kia guy...
The separate sub-forums under the car model listings add more complication than they are worth, for a couple of reasons.
First, in many cases posts that might be made by the owner of on particular sub-model might still be pertinent to the owner of a different one, so you still read every one of the forums anyway, in case you might miss something useful. Alternately, people who might not do this are definitely missing stuff that might be useful to them.
Second, not everyone uses the different sub-model forums consistently. Some people who have a SPec5 (for example) will only post in the Spec5 forum, ever. Others will try to judge if their post is pertinent to all Spec owners, or not, and pick a forum accordingly. Still others (n00bs especially

), will miss the distinction between the forums entirely and use the main one even if there is an appropriate sub-forum.
Third, with the current structure it takes too long for someone who likes to look at all of the different forums to casually surf through all of the model forums...in fact, I can say that if the sub-forums weren't there, I'd surf every forum on there...but with the current structure it takes so long to do it that I don't bother.
Fourth, and probably most compelling, is that doing the separate model sub-forum thing is something to be done to solve a problem...in this case, the problem would be that there is such a massive flood of posts that we need help breaking them down into useful chunks so that the huge volume of information and communication is manageable for the users. As much as we all love Kias, and this cool forum, none of the individual forums here are anywhere near this kind of volume...most get just a few posts/day.
On a side note, I can say from experience that one of the keys to growing a thriving forum community is perceived traffic. The more there is, the better and bigger the community gets. By breaking up the model forums into sub-forums, it artificially reduces the perceived amount of traffic. To use the Spectra forum as an example...to a user, 8 new threads in the sole Spectra forum "feels" like more activity than 3 in the Spec5 forum, 4 in the main Spec forum, and 1 in the other Spec sub-forum.
SO...my suggestion is to collapse the model sub-forums into just the main headings, and let the posters differentiate when needed.
Oh, and I hope this goes without saying, but I love your forum and I appreciate the work you put into it. Thanks for being here!
EDIT: holy crap...this thread is a year and a half old, and this is the only suggestion you ever got? Come on...really?