There has been a resurgence of things retro in Bangkok in the last few years, and one of the most enjoyable, economical, and popular nightlife venues these days is that of the Volkswagen bus cocktail bars. They don't really have a fixed address, phone number, nor website, although you can count on them being in the same place most of the time, but they are a great place to people watch, grab a 100 baht cocktail or 60 baht beer, and really get down with the locals. The Soi Rambutri area, which is opposite Khao San Road on the north side of the temple is the prime location for most of these, 4-5 of them set up shop around dusk and the street is bathed in soft red light, making it very atmospheric.