Rear end rattles & creaking

[Bachster]

I purchased a '98 Boxster about 7 wks. ago (68k) and recently have had some rattling sounds and creaking coming from the rear trunk/suspension area.
Had the creaking checked out - seems the sway bar bushing are the cuprit, so have scheduled a replacement asap.
The rattling perplexed me, so I checked the trunk itself (had the ball joints checked, as another forum had suggested info. that ,if worn, they can cause slow speed rattles) and discovered that the trunk has a particleboard bottom in three pieces below the trunk liner and these would 'rattle' freely when I lightly tapped around the trunk space. I removed them and attached padded strips to the contact points, this seems to have greatly reduced the rattle sounds.

I was wondering if anyone has had similar problems and what they have done about them?

Thanks