Before you change a head unit in a BMW
You should be aware of all the side effects and problems.
Also most common stereo shops will mess up your car.
You need to know which of the three BMW car stereo's you starting
out with. If you have logic 7 you will loose the logic 7 amp because
of the way its hooked up. With Hi Fi it will be possible but still has
major side effects.
The problem list
error from the BMW SOS if you have it
BMW cd changer will no longer work if you have it
PDC will no longer work if you have it.
Why because these things are hooked up to or talk to the BMW
If you take the car into BMW and they need to hook it up to there
Diagnostic computer it will not be able to repair the car until it see's
the original configuration of the car including the BMW radio.
I'm not suggesting Dynavin its just it's well covered and the problems
are the same as with any aftermarket head unit.
Whatever you do don't dispose of the old head unit because you
may need it when you need repairs as the BMW diagnostic computer
will not be able to change values in the sub modules if you need
a repair without a BMW Head Unit installed in the car.