The COMAND unit isn't usually the problem on our cars. It is usually the associated amps, cd changers, voice control
modules, tele-aid modules, and phone modules all on the fiber-optic data bus that causes issues and gremlins.
The COMAND unit is just a radio head with a screen and cd/dvd
drive.
Most of the problems in the systems are caused by communication
difficulties between different manufactuer's products.
Like the Harman-Becker head unit, Bose amp, Alpine CD, and Motorola phone systems. Throw in the Maybach and you have parts from Sony and Pioneer as well.
Until all of these companies can agree on a common communication network and speed, there will be trouble,
Even with just a standard old tape deck.
The new MOST fiber optic system in use since 2003, is a step in
the right direction since it is shared with several other manufactuers. We can suffer the common problems together.
Just ask a BMW tech, He will tell you the same story.
DR.D