from dead stop occasionally I get a clank from the right rear when accelerating.

where to look first... yeah I know, the right rear ;-)

2005 OB 165K miles

Edited August 12, 20169 yr by brus brother

hmm, I guess it sounds too loud to be a shifting brake pad?

 

look at suspension bushings

 

take a look at the diff mounts.

Edited August 12, 20169 yr by 1 Lucky Texan

Checked in the trunk? Spare tire, jack or jack handle could be loose and move around under hard acceleration. 

Any shudders or vibration? Metal on metal sound I would be checking U-joints and any suspension bushings that are back there. 05 has the multi-link rear suspension so lots of places for wear.