I grew up in Miami in the '80s, and back then there was a fast food chain called Taco Viva, but it wasn't nearly as ubiquitous as Taco Bell is today. (Neither was Taco Bell, on that note.) It was a really rare treat back then, since my parents honestly thought ALL Mexican food was super-spicy, to the point where a simple taco or burrito could make real people gag for air and breathe fire like cartoon characters. I recall the logo was a man's face with a big, bushy mustache, and the slogan was "When you say 'taco,' say 'Viva!'"
Anyway, all the Taco Vivas are long-gone now, but I remember them lasting into the '90s, with an occasional location in a mall food court or even an indoor flea market (in Sunrise, FL). Like I said, we hardly ever ate there, but I recall loving it and looking forward to rare trips. There is precious little information about them online, but I was just curious about what people remember, how the food was, how they might have been better or worse than Taco Bell and other Mexican fast food. All I remember was a wet burrito, probably topped with enchilada-style sauce and melted cheese, and in my vague memories, it was GOOD.