Can you give us a little more detail.
There is really nothing behind the front dash panel, that should be rattling.
Are you referring to the floorboard area?
FYI, the PDI service from most dealers is not very good, I would check all fluid levels.
Can you give us a little more detail.just got my 900 on Tuesday not driven it yet just backed it into the garage and noticed there is one heck of a rattle coming from the lower center dash - anybody know how to stop the rattle