Chrysler's success with its minivans is a well-worn story. But even the leader is starting to feel the heat from the Ford Windstar and Honda Odyssey. So for 2001, Chrysler did the first major update since the minivans were overhauled in 1996. This time, the changes are more evolutionary, as Chrysler adds new features and options to keep abreast or leapfrog over its competition.