I'm planning a trip down to San Francisco right after Christmas and I'm wondering if those great taco/liquado trucks I keep reading about on the SF Chowhound pages are open in the winter. I know some of them have erratic hours & that can't be helped, but does anyone actually know if they close down in the winter altogether? Here in Seattle, the only taco trucks I know about are closed until the good weather starts up again in late Spring. But maybe the mild weather in the Bay Area means that trucks like El Ojo de Agua will be there? Please please please say yes. This is one of the few time I'm driving down instead of flying & I can travel all over to get to where I need to go. Any other recommendations for great Mexican food served straight out of the truck(any in SF proper?), as long as they're actually open in December, would be appreciated. I'll be sure to post follow-ups for any of the places I eat.