[mdt]

I've got a M2 Pure being built at the moment and it wasn't possible to spec the higher standard Harmon Kardon stereo system. My existing M135i has the HK system which I'm pretty impressed with.

Is there much difference between the two?

If there is, can I upgrade the Pure's stock system to get it near to the HK system? If so how? I expect the stock system doesn't have the sub-woofers under the seat which I would hope could be retro-fitted.

Any help appreciated.