Re: Stealth Box by JL
I installed my own, mine are also pre-amped, and it was ridiculously easy if you know anything at all about stereos.
They mount to a wide U-shaped bracket which is attached to the floor of your trunk bu drilling through the trunk and bolted in. Each tube sits in two of these. The brackets themselves are only about 1/2" tall, but they connect to straps which wrap around the tube and you can cinch them down. My tubes have never come out or rolled around, and I've had them about 2 and half years. You do need to periodically tighten the straps though.
They sit in my trunk, one on each side, with the backs at the back of the trunk, and the fronts to the rear of the car or the opening of the trunk. They are angled with the angle of the trunk.
If you say the rear of the car is at the bottom of that little thing I just did, they would be the blue lines, the outline of the trunk being the black lines.