Mekas, who is 90, talked about the film and Mars Bar in The Wall Street Journal today. Here's an excerpt from the Q-and-A (I believe it is subscription only to access the piece):
Every city needs some messy, dirty place where you can go and lose yourself and leave some of your dirt there. Paris has. Hamburg has. New York does not have it anymore. This area had Mars Bar. Now it's gone. Now New York is cleaner but not for the better.
And the best thing about the Mars Bar?
You felt very free. The drinks were cheap in price and very often cheap in quality. But you didn't care. It was very open. You always saw the same people, very devoted to the place. From South America, there was this guy Hamlet, who was always there. It made you feel a little bit like home. There was something like a family feeling.