Hi all can someone shed some light on the nav-min option. I understand its function (it's controls the level of cd/radio mute when navigation instructions are given ie fully mute radio/no mute or partial mute on a 1-9 scale.

I don't have this option on my 2005 e53. Why?..

Also on my old 1998 e39 I upgraded all nav to mk4,bm54,16:9 screen etc. I did have nav-min option. But after I used nav coder. I did notice a moth or two later that option had gone and never managed to recover it.

Some explanation on what system nav-min is avail on would be great