Google unveiled its latest self-driving system in a Chrysler Pacifica minivan during a Sunday preview ahead of the Detroit auto show, saying the technology is more reliable and affordable. The announcement came from John Krafcik, head of Google's Waymo unit, whose search for partners to develop and install the company's autonomous driving technology into real cars has so far yielded only an alliance with Fiat Chrysler Automobiles and a pending deal with Honda Motor Co. Headlining a future mobility conference during the show's media preview, Krafcik said Waymo's latest set of self-driving hardware and software incorporated a new array of sensors, including an enhanced vision system, improved radar and laser-based lidar, all developed and built in-house.