Actually one ‘WTB’ section is preferred. When a seller has a item to list they could simply scan the one ‘WTB’ section listing (Chassis, Engines, Parts, Misc) and connect with potential buyers seeking their items.
In effect the ‘WTB’ could instantaneously produce a sale without the seller having to post to the classifieds at all. This would result in a cleaner more efficient classified section and offer a win win scenario for all parties involved (both buyers and sellers).