Oh wow this is retarded, you should forward the email you received to Auto Trader here are the directions:
Forward any suspicious emails to us immediately at
fraudwatch@autotrader.com. Don't change the subject line or send it as an attachment because doing so could prevent us from identifying trends and preventing similar scams. To speak directly to a Fraud Watch Customer Service Representative, call 1-877-742-8040 (Mon.-Fri. 9 a.m.-6 p.m. EST).