Rav Avigdor Miller on Wearing a Tallis Among Gentiles 

Q:
Is it proper to walk down the avenue on Shabbos morning wearing a tallis or are we antagonizing the goyim?
A:
These questions are solved by the circumstances. If you are on Ocean Parkway and Avenue R, so it’s proper to wear a tallis. But if you are, let’s say, on King’s Highway and West 10th Street, so it’s better not to wear a tallis. Not only is it better not to, but you better not! So it depends on the circumstances – many questions can be answered by your own common sense.
Now, to be demonstrative about Judaism is a proper thing. But it must be done in a dignified way; if it’s done in a shlepperisher way, then you’re dragging the honor of Judaism through the mud. So you always have to judge what’s going to redound the credit of the Torah; and that depends on the circumstances.