GMPartsGiant.com offers the wholesale prices for genuine 2011 Buick Regal parts. Parts like Audio System/Speakers & Amplifier are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.0L, 4 Cyl 2.4L. Model Code: CXL 4 DOOR SEDAN, CXL TURBO 4 DOOR SEDAN.