The seller should update their classified ad as items sell, or delete it. As a moderator, I do not delete ads as I have no idea if something is sold or maybe they have multiple items of the same part to sell. Or make more of them, like with the spoiler hold downs.
I agree! If the seller takes time/effort to post for sale items, they have or should have, the responsibility to delete the add. It takes less effort to delete it -- then it did to post it. One click -- gone.