Has anyone had any problems with rattling from the subframe in the rear of the car the part that the rear control arms bolt to. I notice that it moves when I put a floor jack aginst it. Maybe it needs a bushin. Any info will be helpful.

The main report we've had of noise from the rear has been due to bad shock mounts. This is a parts explosion of the suspension that may help you in your search.
Suspension

have you ever placed a floor jack under the rear cross member and and did it move.

I generally jack on the control arm, but I don't recall the sub-frame moving when I did.

My rear subframe moves when I jack it up, I try to jack a side at a time on the control arms now. I would say 8 times out of 10 its the shock mount. I would take a look at the jack/lug wrench carrier mine was loose and it was making tons of noise.