In the mercado latino by Lake Anne. Ordering is difficult w/o spanish fluency, but the carne tacos were very good. Full menu including very non authentic things, such as hamburgers. They do breakfast though, including chorizo and eggs which I plan to check out within the next couple of weeks.
Overall I'm still more in favor of the taco truck, but this is a strong contender.
It is set up much like the place PollyG referenced recently (or at least how that place used to be, I need to run by there again).