First, too often the item is for sale by the individual. We have the classified thread for this specific reason. If it is not the person selling then it is a friend of the seller 'helping' by drumming up some traffic.
Second, the discussions almost always are negative about the choices the current owner made for the vehicle. Imagine if you were be-littled by your peers. Not so nice right? This is where one should error on the safer side and adopt a policy. We currently don't allow Craigslist items in the main part of the forum.
Finally, this topic will remain up for discussion. i.e. provide a venue for constructive criticism. I will confer with the other PNW moderators of this topic.