Here is a detailed write-up:

All about DIRAC and BMW Individual High End Audio System incl. factory visit - The Unofficial BMW M5 Messageboard (m5board.com)

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2011 ///X5 M (On Order)

2009 X5 4.8 M Sport Space Gray/Black Fully Loaded

2007 GMC Yukon XL Denali Loaded and Customised