Would it be possible to allow members to post their sale items to specific categories when they list them, which in turn, would allow for a selection of separate categories when we view them on the forum for sale section?
I have been thinking about that as well. It would be nice if you could go to the sale section and find only rims or CAI's instead of searching through everything. But this would cause subcategories so there might be a problem with that. I have also noticed that a lot of people are using the for sale section to post stuff that they wanted to buy. Which there is a Want to Buy section on this forum.
Don't expect any changes till after the version 4 migration..
As to sections it is doable but a lot more work for the mods/admins and on average most users aren't likely to use them properly.
Just visit the section every hour or so, and there isnt that much to scroll thru.