i have two questions, my car is 39 BMW 540i 1998

1- in secret menu when i chose setteings the keep pressing on menu bottom, the first one onboard .... to change the brightness level, its not showing in my car it shows will i press it nothing.

2- i have the non movable phone in my car that come with the caller id, i dont know what it model, when call is come it shows on the phone screen but not on the Main screen ( LCD ), why? and one of my freinds he own 728il 2000 model same MK2 computer and same screen size 4:3, and also radio options is defreint than mine, he can see the saved radio channels in the screen and many many more.

can you help me on that guys ?