OP's got to be talking about San Diego, home of the Roberto's, Noberto's, Adalberto's, Royberto's, Alberto's, Debsiberto's 24 hour taco shop.
When I moved away from San Diego, I found out that a lot of what I considered Mexican food, was actually regionally specific. Since then, I've learned to make a lot of my favorites for myself. It started out slow, because I had learned to cook American food, but I never thought I'd have to know how to make Mexican food, because there was a great Mexican restaurant on every corner!
I don't have precise recipes, but it really helped me in my quest when I figured out that a red hot sauce does NOT have to be red from tomatoes. I kept putting canned tomatoes/sauce in and wondering why they weren't right?!
I also went through a stage where I thought it should have cilantro and I didn't blend it long enough, so I had a lovely experience where I put a thick hot sauce in one of those squeeze bottles, couldn't get any out, kept trying, and finally ended up exploding the bottle all over my white kitchen.
If you are talking about the hot sauce you find served in a ketchup-style squeeze bottle the basic formula is dried red chiles, soaked in warm water, then put in the blender with some of the water and other items to taste.
I like to use a blend of guajillo (larger and smokier) chiles and chiles de arbol (small and very hot) to get my preferred blend of flavor. I also put in a small amount of olive oil, 1 - 4 cloves garlic, 1/4 of an onion, and plenty of salt. Chiles love salt. It really brings out their flavor. Sometimes I add fresh lime juice.