If it isn't done through Ford, I think it is just marketing. A rose by any other name is a rose. A Mustang endorsed by Shelby or anyone else is still a Mustang. Only if the cars are produced from the factory would I consider the cars special. There are a lot of cool modified 2005/06 Mustangs and kits out there. To me they are still only mustangs. Lee 66 # 869 69 #2055