Thanks, everyone for the tips and advice on how to figure out the authenticity of my father's 2006 "Shelby". Shelby America confirmed from the VIN and photos that the vehicle is not a true Shelby. The mystery to me now is what this car is. My father had several Mustangs, including a '67 fastback that the previous owner used for drag racing and a 2001 Bullitt. Neither has anywhere near the engine power of the 2006. Knowing that the car is not a Shelby, is there a more appropriate forum in which to inquire as to what the vehicle is and to share photos? Below is a photo of the engine for any who might be curious.