Hello and thank you for contacting us. This is Dwayne B. and I’m an expert here and looking forward to assisting you today. If at any point any of my answers aren’t clear please don’t hesitate to ask for clarification. Also, I can only answer the questions you specifically ask and based on the facts that you give so please be sure that you ask the questions you want to ask and provide all necessary facts.
FIrst, as to "what are my options" I need you to be more specific in your question(s) if you could. When we answer general ones like "what are my rights" or "what are my options" we have to give general answers and, invariably, the customer responds with "I already knew that". This type of forum works better if you ask specific questions so we know exactly what you are looking for.
I'll go over your other questions one by one, since they appear to provide information on that general question anyway.
Can I sue them?
Yes, you can sue for slander or libel. However, you have to be aware that those are difficult causes of action because your lawyer's fees will be high, the cases almost never settle, and you will almost certainly have to sue them where they are located. In addition, some eBay agreements have arbitration clauses so you will have to get the lawyer to subpoena a copy of the agreement in place at all time relevant to this action.
In addition, your measure of damages isn't the cost of the car so you can't sue for that amount or at least not phrased like that. You can sue for mental anguish on a slander case and if the car has reduced in value then you can sue for that reduction amount.
Please ask any follow ups you have in this section.