Taco Cabana is offering a special promo to their Facebook fans: If the Dallas Mavericks win tonight (May 31), they’ll post a password on their Facebook page shortly after the game. You can then come to your local TC and say the password to get a free breakfast taco! If the Mavs win, the free breakfast taco will be redeemable only on June 1, from 7-10 a.m.