I have something rattling/squeaking from the passenger's side, rear of the car when I hit small bumps and ripples in the pavement.

I have looked for the problem, and can't seem to narrow it down...it sounds as though it's coming from the area right behind the rear "quarter window" on that side.
Any thoughts/suggestions??

 

If i had to guess i would say that your rear hatch glass is seperating from the frame on the passenger side.

 

The cargo covers can rattle sometimes as well as the rear seat back lock area. By far the worst is when the hatch glass starts to separate from the upper frame. It will drive you mad as it gets worse; it will not get better without repairs. Fold the seat down and see if it helps, if not I would suspect the glass.

 

Parking brake cable rattling?

 

I'll venture a guess- its the rear shock bushes squeaking like newborn mice...