agreed, anyone remember bass shakers? I used to have them in my Supra. Its not really a speaker but a motorized weight that gets signal from the sub amp and vibrates the seats in the same frequency that subbs are playing. they were pretty cool, but it made looking at the road similar to looking out the rearview mirror, blllurrrrryyyy
ninja edit: here they are http://www.smarthome.com/8249p.html