I got sent this info by Brisbane BMW. It looks like it upgrades the base system to something like the Hi-Fi system.
"Dear Tim
For those who appreciate a higher quality audio experience, the Alpine Hi-Fi System is ideal and is now available at Brisbane BMW & Westside BMW. Developed specifically for the unique acoustic conditions of your BMW, the Alpine Hi-Fi System delivers a clarity of sound that simply must be heard to be believed.
The high quality, high performance speakers and powerful Class D amplifier are easily installed and are seamlessly integrated into your BMW. A class-leading two-year BMW warranty adds still more appeal to this premium accessory. The Alpine Hi-Fi System is $1,385 including installation* and is available now at Brisbane BMW & Westside BMW.
To enhance the sheer driving pleasure of your BMW with the Alpine Hi-Fi System contact us at Brisbane BMW on (07) 3853 0000 or Westside BMW on (07) 3363 7500.
Yours sincerely
Martin Roller
Managing Director
Brisbane BMW / Westside BMW"
http://www.bmw.com.au/com/en/owners/...m_DL_Flyer.pdf