Infotainment system on 2010 Portfolio LWB

[MR.O]

My Portfolio has an excellent Bowers and Wilkins sound system. However, one annoying characteristic is the automatic volume increase on different road surfaces. It drives me nuts!! So much that I decided to try to find a way to disable this feature. I enquired with local Jag franchise who didn't really seem interested and told me it was a safety feature that could not be de-activated. Can anyone confirm this or know of anyone that can?