Yes - I see that. It is a 3 series convertible. And you have noted that in your first post. But you can always get another one. Like a 328 coupe.
On the other hand, if you have test driven the 1 series enough, and like its value proposition (I liked the value proposition much better than a 3 coupe), then no questions. Get the 128...
But if you like the 3 better, then you may be making that comparison everyday.