Eletrical problems BMW says bad radio and LCM

[broken]

So this is my problem:
4 weeks ago I started the x5 and the sound coming from the speakers sounded like it was playing from an submarine under water. Then went away totaly in the next few days.
Dsp and phone dissapeared from menu. Radio and changer started and worked.

2 weeks later the 16:9 screen started to get black ones in a wile and with in a week it gote totaly black.

Self levling intact came on a few times, i think if i remeber correct when the gps gote going.

Once the car wanted code in 16:9 before i could drive away.

Car behaving verry strang light whent on after i took out the key, auto light dissapeared, this happend and then and drained the battery once after charning its started as before with same problems. Noturn signal in dash but worked outside.

Drove one more week, left the kids in school and got back to the car 5min later, battery totaly dead. Try to jump start no succses, changed battery to new and it started as before.
Now the Nav came back for about five minutes then frozzen scrren and then black. Still no sound.

Drove one week with the new battery.
I get out to start the car, start motor cranks but wount fire try different keys no luck.
Next day it starts as normal but with same fauls as before.
Next day no battery, chared it and drove to dealer.

Dealer says, no contact with radio modul and no contact with LCM. They whant to repace both for something like 3000dollar.

The car has DSP, cd-changer nav mk III, 16:9 and cordless seimens.
4,4v8 2001

Ingnition swith changed when problem started no change, new battery I have driven with a voltmeter in cigaretlighter and it showes 13,7v wile driving. Fuses cheaked.

So what shold i start with new radiomodul and se if sound and screen comes back to life? Is it possible for a bad radiomodul to shot down dsp, phone and nav? I now they can steel power.

Its a shame on a nice locomotiv as the x5 still is that the eletrical is so sensitive.

I will pick it up from the stealers to morrow, please any thoughts!
BR Broken
Sweden