As it has done from time to time throughout its 103-year history, Buick is rethinking, renewing, revising and rationalizing its model lineup. The Buick Lucerne replaced the Park Avenue and LeSabre when launched as a 2006 model. The Lucerne benefits greatly from the structure and chassis hardware that it shares with the recently launched Cadillac DTS. In this, Lucerne is not breaking tradition but confirming it. The biggest Buicks have shared body structure with Cadillacs since the 1930s, if not before; and they have shared significant chassis pieces since 1965.