E90 Speaker/amp Upgrade

[Lurcher]

Afternoon everyone!

I'm still waiting on the call from Westerly Exeter to tell me that my 320d M Sport is ready to collect.

I'm a bit of an audiophile and have heard from numerous people that the stereo in most 3 series Beemers is sadly lacking.

Certainly was the case in my A3. :(

It seems sensible to keep the head unit and replace the speakers. Of course, I don't even know what the car has fitted yet but assume there are components in the front doors, two subs under the front seats and two on the back shelf. Any (reasonably priced) recommendations? Don't want to blow the windows out :wacko:- I imagine a 4x 100w amp would suffice! Thanks, Dave :D