Because I showed pictures of 4th generation Firebirds and New Edge Mustangs to the same couple of guys who said the AMG was a "Zuhälterauto" and they had nothing bad to say about it. They actually didn't know the cars. They said the Firebird looked like a sports car of a rich guy and the Mustang they asked if it was a Ford Sierra, which surprised me but I kind of can see where they are coming from. Then I showed a picture of another 4th generation Firebird, this time black and they said KITT.

But I guess if I had shown the picture of a black Corvette or any low profile black sports car they don't know they would also have said KITT.
Then since they didn't have any bad stereotypes for the cars I showed it to a few other Austrians and nobody knew what the Firebird was and had no stereotype for it. The opinions ranged from sports car, cool or futuristic. One asked if it was a Corvette. But nothing bad. The Mustang a couple of people knew though.
So is there really a stereotype for the Firebird 4th generation in Austria? It doesn't look like it. Or the Mustang for that matter. But somehow the Mustang seems more obviously an American car for people. The Firebird they don't seem to know what it is. But nobody said anything bad about it.
Thanks guys.