bolting sub box down

I have an 05 explorer xlt. It has third row seating. I took part of the third row out and folded the other part down. What do you guys do to bolt your boxes down? It's a 7 cube box with a dc level 6 18 inverted. I also have to mount a huge crescendo 5500 and an agm battery. Pics would be awesome so I can get some ideas.

Just bolt it down using metal L brackets. Straight to the body.