I grew up with sidewalk vendors/carts/food trucks in Taiwan. Street food = awesome taste:cost value (for the most part). I've heard people poke fun or turn their noses up at the idea of eating from a "roach coach". Suckas didn't know what they were missing until the recent food truck craze popularized street eats. So apparently now it is "cool". Can you see me rolling my eyes right now?
Mariscos German has been around long before the craze and have a huge fan base, so this is likely to be old news for many. Fish tacos, fresh seafood tacos, ceviche, tostadas, & complimentary seafood soup can be had at super low prices. Best bang for the buck is the $1 fish taco, which I daresay easily ranks in San Diego's top 5. You could either fill up on that, or have something more interesting.
Grab a handful of napkins and a fork. You're gonna need 'em.
After a heavy hitter like the Marlin taco, I like to have something light and refreshing:
Mariscos German serves various kinds of ceviche-topped tostadas. Each one comes with a nice big hunk of avocado too! The tostada is pretty huge and is a lunch entree in itself, so if you're not a big eater, I would suggest sharing with another person.
Oh, and don't forget to pick up your free cup of seafood veggie soup. It's good stuff.