In Oxnard, Check out Tacos La Costa. A very small place off Saviers Road, Right across the street from the Oxnard DMV location. It gets pretty packed at that place, and its pretty good. You could also try El Taco De Mexico also on Saviers Road. There are a few "TDM's" In Oxnard, there is also a good one off Fifth Street, which is really small, kind of run down, but still serving pretty good Carne Asada. As for Fish Tacos in Oxnard, Pepe's Mexican food stand in (the infamous) Silverstrand Beach is pretty well known, although I've never had their fish tacos. I've had their Carne Asada, and it as well is pretty good.
The there is El Chilito which has REALLY good Carne, and they actually have a guy making them outside off a Vertical Gyro broiler. I probably should've suggested this place first. I tried their Carne a few weeks ago and it was really good (but the chilie rellenos weren't the best, but thats another subject)
Tacos La Costa
-4200 Saviers Rd, Oxnard 93033
El Taco De Mexico
-3101 Saviers Rd., Oxnard
(I don't know off the Fifth street address, but its right off Oxnard Blvd)
349 W. Channel Islands Blvd, Port Hueneme
Phone: (805) 985-8229
-Pepe's Mexican Food
200 Rossmore Dr, Oxnard
(Off Victoria, Straight down past Channel Islands Blvd. follow the road
and it will take you right up to it)
This post probably comes a little late, but for everyone else checking this thread out, and would be in Oxnard, come check these places out for your taco fix..