Having lived in Charlotte over 10 years, I can't believe I hadn't heard of this place till 2012!
Authentic, hole in the wall type Mexican restaurant that gets very, very busy every day. Excellent and very friendly waiting staff. Seeing that we're Indians and that we probably like hot food, the owner brought out a green colored salsa (Guac based) in addition to the 2 red salsas given out with the chips. We LOVE the green salsa - really spicy and flavorful... haven't you sometimes felt like eating on even when your mouth is burning hot? Its like that!
Over the last few times that we've gone there, we've ordered a number of dishes - california burrito, la unica burrito, carne asada tacos, arros con pollo, camarones al chipotle, pechuga de pollo ala mexicana, chimmichanga dinner, etc... you get the picture. All were great; better than we've had anywhere in Charlotte or elsewhere. Not one case where we even felt like the dish or experience could've been better.
A recommendation - the place tends to get very packed and depending on what time and day you decide to go, you may have to wait to be seated. You can also phone in your order and pick it up once ready.