I would say they have part of what they want....an email address and possibly a name and/or phone number if you gave it in the email.  Just be careful of any phishing emails you may receive in future.

Did you take any notice of what the items were that the seller had sold on the account and when they were sold?  It sounds to me like it may have been a hijacked account.  If it had been inactive for a while and the car was not the sort of thing the account owner had been selling then it is a good chance that it was hijacked.