Habanero is a Mexican taco truck that pulls up at scheduled locations in Hongdae and neighboring area. Unfortunately, not much English web presence, however, you can get a feel for their menu on their Korean blog. They often post updates on whenever they’ve got something going on elsewhere and location where to find the truck. But usually, you can find the truck by referring to the below map. The map coordinates are accurate as of 2010, according to their blog. But judging from Naver food bloggers, people are still going there in droves.