I've been looking for the same type of solution. Short of setting up a computer hookup through the AUX input (i.e. onboard computer), there's no way of doing this for E46M3 with Nav. Even with the Crutchfield solution. Guess we'll just have to wait AlpineWhiteE46.
If anyone has a better solution, please let us know.
There are several threads about this in different areas of the forum, but no good solution for folks with NAV.
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