Waymo, the standalone venture that emerged from Google’s self-driving car project, on Monday unveiled a fleet of 100 Chrysler Pacifica hybrid minivans with the latest high-tech sensors, telematics, and other gear designed for fully autonomous operation. Modifications were made to several parts of the Pacifica — including its electrical, powertrain, chassis and structural systems — to optimize it for fully autonomous driving. With the additional computer equipment, the cars will undergo more challenging tests.