I have frequented the forums since getting my car a few months ago and have read a few complaints about the search function.
Google to the rescue
More search help - Web Search Help shows some of tips/tricks for Google searches that many folks are not aware of.
One of my favorites is: Google allows you to specify that your search results must come from a given website. For example, the query
spark plugs site:insightcentral.net
will return pages that have the term "spark plugs" but
ONLY from insightcentral.net.
Another tool that Google provides that is easy to use is their Search Tools. You may notice that when you typed in the website above, to the left of the Google listings, you will see Search Tools. Click on it and you will see a set pre-defined search time frames. The default is everything but you can change that by clicking on one of the other selections. Or if you don't see what you want, you can go to custom and pick whatever time frame suits you.
Finally, for us, most of the time we want to search only in the 1st generation forums. That specific website is
Honda Insight Forum 1st-Gen Discussion - Insight Central: Honda Insight Forum
So if you want to search for spark plugs
ONLY in the 1st generation forum, you would enter the search term like this:
spark plugs site:insightcentral.net/forums/honda-insight-forum-1st-gen-discussion/
I use Chrome so know this queries work in Chrome. I tried them on FF and IE and they seem to work as well.
The search bar at the top of the page is good but being able to tweak your search specifically for what you want is a good thing.