I lost the authenticity card that came with my '04 Cobra. After much frustration trying to get info from Ford, I called 800-fordstv. After I gave the customer service guy my vin, he gave me the build number and the build date. He is also sending me an authenticity card. If the card is a replacement it's $40. If it's your first request, it's free. By the way, they answer the phone "Ford Performance".