Yes. My Spyder was so resonant that the back control cavity cover plate rattled. I placed some small strips of thin cotton cloth between the cover plate and the wooden edge of the cavity and that stopped the rattle when I replaced the cover and tightened the screws.
It took me quite awhile to figure out what was causing the rattle. I originally thought it was a string, or the bridge or a loose pickup screw.
These basses are so resonant that everything vibrates, which can sometimes make it challenging to track down the source of a rattle.
You might also want to check to make sure the cover plate isn't warped slightly - if it is, it won't make good contact with the edge of the cavity. You'll want to correct this as much as possible prior to doing anything else.