The OC Weekly has a good read about Santa Ana's taco trucks. Check out the postings from Los Hermanos Lonchera sin Frontera at twitter.com/loshermanosLSF. They've certainly taken their cue from the Kogi folks.
I lived in Japan for a year in the '90s, and I spent an inordinate amount of Tokyo time searching for a half-decent burrito. The best I found was at a restaurant called El Sol in the Umejima district, but the most interesting was from a beaten up roach coach in Shibuya. The owner had decorated the green truck with Don't Mess with Texas stickers, and he was quick to warn me that "Japanese no like beans," so naturally the burrito was beanless. I'll have to dig up my photo and post it up, but in the meantime the photo above is from Garden Grove's Korean District.