You could fit the latest NBT system if you wanted to mess around about with trims etc.

This is the ibus NBT emulator....

BMW NBT emulator for iBus cars (e46, e38, e39, e53, e83) - GERMANIKS.COM

I am new to E83's, but have done loads of retrofits before on BMWs, started with my E46 back in 2002 with the widescreen MKIII system back before loads of info on the net and no retrofit kit available. Think I did the first retrofit on a 2005 1 Series when I got it. Did the E91 as well, including dash change.

But the problem for me with this is I like it to look completely OEM and not sure about screen housing etc.
Did the later E83s get a non pop up screen that was bigger, like the 2 series did?
Is the 1 series screen template the same as the X3 one?

iDrive controller is not an issue, NBT unit could be hidden away and the faceplate (controls) put in place on an extended cable, but the screen needs to look oem.

Maybe someone has done it on here already, I have not looked as I only picked up an E83 today.

Having said that, I had it in my F25 and although it is good, all I used was bluetooth streaming 95% of the time, which I could add to the aux input for £15.

But could be a fun project.