I put an eye bolt on each side and a ratchet strap over the top of the m/w, and the battery and the pet cool.... but mine is located under the galley. I put an old piece of rug under the ratchet to keep it from scratching anything.
If you go to the link below, last page, first pic, you can see it.. I saved the Styrofoam that held the turntable and just put it back inside as originally packed.