Z4 Speaker upgrade?

[scubanorthy]

All

I recently bought a 2003 Z4, with the standard 6 speaker / Business CD head unit audio system (which I've added an excellent DICE iPod system too).

The sound is pretty poor really - I am aware that this is not a unique problem I am experiencing. Has anyone changed 'just' the speakers for better ones, I don't esp want to play around with a new head unit or amps etc.

I would appreciate your input

Regards

Dave