I was walking back home from the gym, and noticed a big white taco truck on Mariposa across from Jackson playground in Potrero Hill, close to Arkansas. It's owned by Gaby and Liz (their names are painted outside). To reward myself, I had one pastor and one pollo asado taco. Neither was as nice as Toyanese, a little less flavorful, but still very good. I see Mexican workers on lunch break eating the tortas by the truck all the time, so I bet those are good if you're hungry. I wouldn't drive to Potrero to eat these tacos (stay away from here anyway!), but it's worth stopping by if you're in the neighborhood and want a cheap snack. Gaby and Liz are here M-F from 9 to 5 and Sat. from 9-12.