The Buick Lucerne was a full-size upscale sedan sold by the Buick division of General Motors. Introduced at the 2005 Chicago Auto Show, the Lucerne replaced both the Park Avenue and the LeSabre for the 2006 model year. The Lucerne served as Buick's flagship through the 2011 model year, when it was discontinued. The Lucerne was based on a revised G platform; however GM continued to refer to it as the H platform. It has been replaced as the division's flagship by an upscaled second generation Buick LaCrosse.