[wishihadahorse]

going over any irregular surface ... local wrench could find nothing loose underneath. Just fishing here, but is there any chance that the culprit is rear subframe bushings? P.S. - standard (non-airmatic) suspension; 2003.

 

[Roadking999]

check your jack, strap tight

 

[wishihadahorse]

yup ... did that (but thanks for the suggestion); even removed everything from trunk. sounds just like a loose jack rattling around back there, but coming from underneath.