yer, same i've got two peices of hook velcro stuck back to back between the sub and my boot carpet...
ive also velcroed my toolbox into the boot too.
so far nothing has moved thru some fairly extreme manuevers
Rosewood EAII Fairmont 02/90. MPFI 3.9L (formerly CFI), 4spd BTR Auto. Skyline geared 3.45g open center 28 spline 4 pinion differential & axles. 2 1/2" Cat Back Exhaust. King Super Low Springs. Sound: Equalization and amplification by Clarion; Head unit by Sony, Front, Rears and Sub by Pioneer. Planned mods - t5, Extractors, Painting Grey Strips and new front and rear bar.