I've mentioned most of these things before... some of them are technical in nature, and some are content related.
When I log in and go to a particular forum, every thread with a new post since my previous login is shown (correctly), but every thread made BEFORE my previous login shows "no new posts". Shouldn't the older threads show as unread (with new posts) if I haven't ever read it? That's how it works on other forums.
Also, when using the "Browse All" feature, there is no indication that I have posted in a thread. But, if I go the the actual sub-forum that contains the thread I posted in, it does show that I've posted. Since I prefer to use the Browse All feature, it's very frustrating when trying to keep up with threads I've posted in.
Also, if you insist on having so many sub-forums, could you please show what forum a thread is contained in when using the Browse All feature. Since people are now posting in "catagories", I've noticed that the title descriptions have become more vague, probably because the posters think that everybody looking at their thread knows what kind of sled they're talking about just based on which forum it's posted in. And, I've also noticed several multi-sub-forum posts with the same title, which can be frustrating. Those posts would be easier to follow if I could tell which sub-forum they are posted in.
Please tell me you're working on the compatibility problems with IE (not just the speed issue, but things like user profiles not having full functionality). I know you (and a lot of other people) think Firefox is better. But, there are those of us that don't have a choice regarding which browser we use in certain places... like work. I can get online for personal use at work during breaks, but I can't load "non-authorized" software (including a different browser) on my computer at work. Besides, even though I have FF and Chrome loaded on both my XP machine and my WIN7 machine at home, I am apparently one of the few that thinks IE8 is actually a pretty good browser.
I think you need a legit FAQ section. And the very first thing I recommend putting in it is a comprehensive tutorial on how to do more than just a basic search. After that, you could put things like... descriptions of all the features available on the forum and how to use them - interpret them - disable/enable them - etc... You could have topics like "posting pictures", "experience points", "user profile", "shout box", "multi-quoting", "customizing how you view the forum", "the garage", "calendar", etc., etc., etc.. And there should be a direct link to the FAQ on the top of every page. Don't bury it in a drop down menu.
You should also think about making a sled brand FAQ that's shown in the sled brand sub-forums. In this FAQ there could be a model description/manufacturer timeline, common abbreviations, tech articles or links to popular/helpful tech threads.
And, some may disagree, but I still think it would be a good thing to allow users to provide feedback regarding the worth of another user's posts. As it stands now, the "experience points" system may lead some casual readers to mistakenly think that a user knows what he is talking about based on some ranking system affected by how many pictures he posted, or how long he's been here. I know the rep system was in no way perfect, but at least the big red bar by a members' name was a good indication that you might take what they said with a grain of salt.
Well, that's all I have time to type up at the moment... I'm sure I'll think of more. Thanks for asking.