Before you go HERP DERP THAT STUPIB listen to this.
Say you own an Ion and want to sell it, so you skip along to the Electronic Marker BST forum to post it up, but... When in the thread creation thing, theres a little dropdown box that asks what manufacturer the gun is, obviously you choose Smart Parts, and the thread will be posted twice, once in the Electronic Markers forum, and once in a dedicated Smart Parts BST section.
So if someone posts in the Smart Parts forum on the Ion guys thread, it also appears as a post in the Electronic Markers thing, and vice versa, the two threads would be linked, so whatever happens in one happens in another.
I think it would work well since if someone wanted say a Vice, they dont have to hoarde through hundreds of BST threads in the Electronic Markers forum, instead they can just flick through the Bob Long section and find Vice's easily.