There is a bracket at the bottom with two bolts. There is also an allen bolt at the top behind the fuse box which secures the sub at the top.
Below is from my Stealthbox installation but this uses the OEM sub bolt locations.
1. The bottom bracket: (shown attached to the JL box, but this bracket is from the OEM box found at the bottom of the box)
2. The top mount which is behind the fuse box: (allen bolt is OEM)
