Well apparently it is the parking brake cable that needs adjusting that's causing the rattle as Brian mentioned, and Peter confirmed.
I got underneath the car and shook the cables that run just underneath the axle drive. It produced the exact sound I've been hearing at BOTH wheels, so apparently I need to tighten/adjust the parking brake.
Read some posts on how to adjust from down there and the only 10 or 11mm (forget size) bolt I saw I tried to tighten, and it would NOT budge. I sure hope that doesn't mean the cable is stretched to its limit. In its current state, the parking brake almost is to floorboard before it locks.
I guess I'll take it to a local shop and have them adjust it (can't be more than .5 hours to adjust can it?) or try again myself at each rear wheel tommorrow.
Thanks again for the responses