How can you list a wrong item for sale? Seems strange to me.

Maybe this clause in TOS will give a hint:

Car is advertised elsewhere so I have the right to remove it from eBay at any time.

And that is why exactly, I believe, it is against eBay rules to advertise elsewhere.  People would be listing here, say they advertise elsewhere, then sell off eBay and not pay any fees.  It is a fraud.