[razor1965]

I'm considering an M340d that I've seen. Ticks all the boxes except the HIFI is the bog-standard one and has no speakers in the corner near the mirrors (I'm sure there's a scientific name for them). My question is, is it possible/advisable to get the speaker system upgraded? Would need a specialist hifi installer I imagine but would it disturb any functionality in the car such as bluetooth , etc....

[jayakrishnanv]

It is not only the subwoofers near the A pillar or doors...if you want to retrofit you need the door panel with the speakers, change the top of the dashboard to have the speaker in the dash top, then door cards to have the speakers, change the under the seat ones, etc. on top with all thee wirings done and may need coding as well...

If all the other options you are looking for is ticking the boxes for the car then see the aftermarket subwoofer options which can be fitted and it will not affect the existing bluetooth options. However when such an install happens you need to make sure the right adapters are used than splitting and splicing the cables with a professional install to keep your warranty.

[RichardM]

They are tweeters that would be there. The base system isn't actually that bad. Like you I assumed I'd need to upgrade it but I've not bothered as it's just about ok.

A place near me specialises in BMW upgrades and you'd end up with something much better than HK. The only downside other than cost is them fitting the amplifier in the boot.
https://www.audiofile-incar.co.uk/au...7-and-x-series