All car manufacturers including BMW go through the war with production cost and productivity. Because these companies are car manufacturers,
naturally they are more focused on car’s capability than audio quality and are often forced to make bitter compromises when in come to sounds.
(This includes the basic audio and premium audio options.)
Every speaker unit has important factors that determine the quality of sound that allows the speaker to vocalize the music that recording engineers meticulously recorded.
These are magnet and surround materials, voice coil and surround designs, suspension, and cone quality.
In many cases, OEM AUDIOs often use low quality paper cone and plastic basket tweeters or even omit it at time for cost reduction,
(Domestic car manufacturers are known for using units that cost around USD $3 and German car manufacturers aren’t too much different.)
When compared to specification of the import cars, identical trimming is applied to almost all cars to deliver the cars as soon as possible.
You could easily assume that this will eliminate any consideration of sound quality.
(Even if special option is selected to individualized order, this result in minimum of couple of months of wait for production, expensive additional fee, increased additional taxes due to increased car price.)
The result can be easily estimated.
Initial feeling of the sound may be plausible but that’s nothing better than hazy and rough sound as if it’s drowned