I have a strut mount that I couldn't torque down properly because the little flat spot rounded while I was torquing (pretty sure that was my fault) and couldn't figure out the rattle for a long time. Check the top nut on your struts, just to be sure. Mine doesn't rattle all the time, but when it does, it sounds like the hatch is about to fall off.
For those interested - it's been off the road for body work and paint for a year, so it'll be fixed before I drive it this spring.