I saw one about a month ago in El Cajon. I parked next to it. My guess is that they were either on their way to or coming back from Viejas.
After seeing it up close parked, I 100% convinced it's just as ugly as I originally thought. So tiny too inside and out. My M3 looked like it dwarfed the little 120i.
The one I saw had Front BC plates... or maybe Sonora, can't remember.