Toyota has made a new development in in-car navigation and has combined it with specific Nintendo DS and 3DS software, to allow interaction between the handheld console and the sat-nav.
While buying the Toyota nav system for your car is hardly cheap - 206, 850 yen (£1,620), the Nintendo linked application is a little more realistic at 7,329 yen (£57), though still expensive for a bit of DS software.
Known as Kuruma de DS, it comes in a little cartridge like a game would and hooks up wirelessly - thanks to Bluetooth technology - to the in-car system. The handheld can then be used as a remote for the sat-nav, complete with Nintendo Mii characters. From there you can input destinations, read the speedometer, see how far is left on the journey, check out sightseeing information and take part in simple quizzes.
Presumably this is designed for a passenger to tweak the sat-nav system without sticking their greasy fingers all over your nice new Toyota. However it seems like it could be a great application for child passengers - with the control features disabled - by allowing them to see exactly how far you have to go on your journey, as well as keeping them entertained with Nintendo visuals and the aforementioned quizzes.
It should at least bring an end to "are we there yet" questions.