Following on from criticism by members that cars being listed for sale in this section can get killed by excessive negative comment from others, now only the thread starter (OP) can post replies to his / her own for sale listing.
Anyone who wants to ask a question about the car being listed will need to PM the seller directly. The seller is then at liberty to reply via PM or If they wish, post an answer for others to read on their for sale thread - in much the same way that eBay operates an 'ask the seller a question' button.
More on the requests for this can be found here
Making Classified ads read only