The other reason we dont post about active auctions is the possibility of collusion. Say some one see a truck they really want and because were such a great group of people that would never snipe something from some one else, makes a statement like "hey I hope to bid on this and it sure would be nice if no one else would bid so I could get it cheap" and one or two members post up and say "sure I wont bid against you", that would be collusion. Or some other member sees a truck he really wants and decides he's going to post something really bad about this truck like maybe the block has a really big hole in it but the description doesn't say that, so he thinks he might be able to steer some bidders away that way. The rule is there so if there is no discussion of active auctions then there is no possibility of the above happening.
In the case of rare items, if you dont plan to bid on it and just want to know more about it, save the pictures, sale and lot numbers until the day after the auction closes and then start your post about it. If its something you think you might bid on because its rare and valuable I doubt you would want the extra attention your going to bring to the auction before its over. In that case if you want to research something for value, your kinda on your own on that because as soon as you bring it up here, if its rare, people on this site are going to jump on it.
The only auction post that I dont go ballisticon rule infractionsfor are the reallyreally big items that I know people hear arent really in the running for anyways, Like the Torpedo recover boat that was up for sale a few years ago. If the lot is going for several hundred grand, I doubt any extra attention SS members are going to give it are going to drive up the bids by that much.