One of the most interesting systems we have done for a while now - a 5.1 Dolby Digital surround sound cinema system in a stunning E39 M5. A 7 channel Diamond Audio D65.2 amplifier powers Diamond Audio speakers front, centre and rear, and a pair of free air 12" subwoofers on a custom rear shelf. Surround processing is managed by an Alpine PXA-H701 with a 500GB media server holding hundreds of movies, and an Alpine head unit with remote face install provides control of the system upfront.