As far as I know ( that's not saying much ) these bushes are pressed in and do not have any cir-clips.
Hmm, Hmm... I should have looked at the pix below before bashing out the tosh above. These LOOK a bit SPECIAL. Are they some kind of an UPGRADE ? to the known weak spot of E46s. I was thinking about standard rubber/aluminium type, when I wrote the above.