I know, taco trucks?!?! Trust me on this one. Everything in LA is on four wheels and good Mexican food is no exception.
I recently discovered Tacos El Pique, a Taco Truck in LA's highland park. I went back 3 times in the span of one week even though I live 30 minutes away! But no need to limit yourself. After hours just look for the light trucks parked in heavily Hispanic areas and look for the ones with the lines. The locals know.
Bear in mind that these are "D.F." style tacos. That is, soft tacos. There is no lettuce or a crispy tortilla shell in sight. These tacos are small flour tortillas, topped with your choice of meat, onions, sauce and radishes and cucumbers (to cool you off) on the side. I loved the carne asada and carnitas tacos. My wife was partial to the chicken one best. But at a dollar a piece, get one of each and make up your own mind. Oh, and top the whole thing off with a Mexican soft drink.
By the way, D.F. stands for Mexico's Distrito Federal or Federal District, which encompasses Mexico City. It's like the D.C. in Washington D.C.
Don't expect luxury, this is after all a taco truck on a street lined with auto repair shops. There are no seats beyond a bench or two, but as you sit in front of the truck, inhaling the tacos with salsa dripping down your chin, you won't care where you are.