Buick's largest car adds an optional navigation system for 2007. Lucerne shares its basic architecture and V8 engine with the Cadillac DTS. CX and CXL V6 models have a 197-hp V6. CXL V8 and the top-line CXS have a 275-hp V8. A 4-speed automatic is the sole transmission. Lucernes come with front bucket seats and a center console for five-passenger seating. CX and CXL models seat six with an available front bench. Front side airbags, curtain side airbags, ABS, and OnStar assistance are standard. An antiskid system is standard on CXS, optional on CXL V8. Exclusive to CXS is GM's automatic-adjusting Magnetic Ride Control suspension. Leather upholstery is standard on CXLs and CXS, unavailable on CX. Available features include remote engine start and heated and cooled front seats. A navigation system is newly optional on CXL and CXS.