upgrading my 2005 x5 stereo

[novfilms]

my 2005 x5 has the stock stereo system in it (with nav & sirius) but i'd like to upgrade the sound. not sure if there's any good place to put an amplifier (suggestions) but i think upgrading the speakers (component system?) might help. i recently put a new alpine head unit into a 1992 mbz wagon that i'm having our recently driving permited daughter use until she's got some driving experience. when i bought it new i was still in those heady days of great music whatever the cost and apparently (i'd forgotten) replaced all the speakers, put in a sub and lots of power. with the new head unit it sounds like a home stereo and blows away the stock x5 system. my wife (who drives the x5) is jealous! what can i do realistically for the x5?

thanks

alan

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