The Citybeat has an article about how Mexican restaurants have changed in Los Angeles over the past two decades, noting that carnitas was a rarity in town 20 years ago:
Mexican food in Los Angeles has changed a lot over the past two decades. Not that long ago, few restaurants here offered any meats other than chicken or beef, and the only sauces were green or red chili or the mild stuff they pour over enchiladas. Places that served carnitas advertised it on their sign, and homesick Mexicans and savvy diners alike hit the brakes when they saw eateries named Carnitas El Tarasco or Carnitas Patzcuaro.
Meanwhile, over at the LA Weekly, they have their 99 essential restaurants mapped out, which include El Parian, Guelaguetza, La Casita Mexicana, etc.