Before the Tenderloin is remade into another residential neighborhood for rich techies, come bask in its still colorful ethnicity, like legendary banh mi sandwiches, this Sunday at its block party from 11 to 4. It’s one of the regular events around town where blocks are restricted to pedestrians and cars are towed away. Besides the samples of exotic street food, this year will mark a celebration of the Thai New Year. (The adjacent blocks are known as Little Saigon). It’s also a great chance to visit the historic Tenderloin Museum and the Tenderloin Community Garden. It’s bound to be a jammed Sunday. Don’t even think about driving.