Adriano,
You certainly have nothing to apologize for. ‘Air cars’ is a term used in this hobby to describe a vehicle thats history is doubtful. More specifically, when an entire car is assembled from one piece of an original Shelby. Like finding a Shelby Vin Plate and building an entire Shelby from it. Conversely, sometimes an original car could have sustained damaged, like an original Cobra being raced and having a significant amount of its body work replaced due to an accident. Years later, someone ‘finds’ the discarded parts and decides to build a Cobra out of them. Now you have an ‘air car’. This phenomenon isn’t limited to Shelbys. Ferraris and Jaguars suffer with the same affliction, as I’m sure many other Marques do.