This is very tough, but I'm going to go way back with the Ford Model T. It essentially brought the automobile to the masses, and popularized it in ways not seen before. As the quote goes, it "put America on wheels". So in that sense, it was pretty damn iconic.
edit. I guess it wasn't that tough after all. Well at least, that's what came to my head instantly. I'm interested to hear what you put.
i was waiting on a moment, but the moment never came. all the billion other moments, were just slipping all away. i must have been tripping, we're just slipping all away. just ego tripping.