Consequences of a Pop up food cart in Saigon?

What are the consequences of opening a little pop up food cart in Saigon? Street gangs or the police will protect their territory? i'd like to be the old ladies that sells food of her motorbike lol !

A work permit would be your first consideration.

It's not unheard of:

Weiners on Wheels

I know the German guy and it hasnt been all plain sailing for him. Out of all the photos in that link the last guy is the only one you could class as being a real success and he is one of a group of partners who own the American BBQ Place in D1 facing the canal but its a full blown 3 storey restaurant.