You drill a small hole through the trunk liner and attach a long stud into an existing bracket behind the trunk liner on the passenger side, through the hole you drill, and it protrudes out into the trunk. There's a small, corresponding hole in the back of the box, once lined up, you slide the box in place, and the stud into the box, and attach with washer and not and tighten snug. Trust me, it goes no where, very solid.
And yes, it's sealed.
2010 2SS/RS CGM
American Racing Headers, Magnaflow axle back, Roto-Fab CAI, Audio Integrations Sub box, Alpine Type R 10, Alpine MRP-500 amp, Pro Clips iPhone Mount