Complex sentence: GM ceased production of the Northstar engine in July 2010, with the final cars to receive it, the Cadillac DTS, Buick Lucerne, and Cadillac STS, rolling off the line in 2011.
Split into simpler sentences: GM ceased production of the Northstar engine in July 2010. Production of the final cars to include the engine, the Cadillac DTS, Buick Lucerne, and Cadillac STS, ended in 2011.