Honda Odyssey Poor Handling
 

I've got a problem w/ my mini-van that I have not been able to
resolve.

The symptoms are
* noisy ride - When new, the ride was nice and quiet. For the last 40K
miles or so (now at 80K).
* bumpy ride - it feels as though I can feel every slight bump on the
road.
* drift - Sometimes the car feels like its briefly drifting (or
lurching) sideways. Everyday on the way home from work, i hit a couple
of patches on the groved highway that makes it feel like my car drifts
several inches to the left when the wheel hit these slight bumps.
This also happens when I hit a slightly bumpy patch on a turn. It
feels like the wheels are jiggling so much that they are leaving the
road and causing me to drift on the dry pavement. It feels a little
like hydroplaning.

30K miles ago I had a trusted mechanic look at it and found nothing.
This week we took it to the Honda dealer. They said that the struts
and shocks are fine. They want to run diagnostics but I'm reluctant.

Tire info:
* I suppose its possible that the ride started to deteriorate w/ my
first set of Peerless replacement tires.
* I'm currently on a brand new set of Peerless tires.
* When they replaced them this summer they said that I had unusual
wear on them. The ride did not improve with the new set of tires.

Thoughts?
-dan