Let's say you liked adding GPS to your Nintendo DS. How about adding a Nintendo DS to your GPS? Toyota is trying just that through a new Smart Navi GPS unit in its Estima Hybrid minivan that will let passengers control the mapping system. Load up the Bluetooth-equipped Kuruma de DS cartridge and you can enter directions from the back seat instead of waiting for the driver's next chance at a red light. The automaker is also hoping to cut the "are we there yet?" levels of ennui to a minimum by providing trivia questions, hand-drawn map notes and a surfeit of tourist info. Mii characters speak out text information, and you can even use the car as a speaker system in the event your Starfox game needs that much more audio immersion. Estima buyers can get the new Smart Navi and Kuruma de DS in Japan on June 1st, although the $2,586 equivalent price for the GPS, the $92 cartridge and the cost of the Nintendo console itself might be too rich when you don't need a navigator to tell you that the princess is in another castle.