Planning on replacing the stock BOSE sub with an aftermarket sub and amplifier. So far I've only been able to find a Kicker Comp 07C104 10" 4-ohm subwoofer from Crutchfield http://www.crutchfield.com/p_2067C104/Kicker-Comp-07C104.html?tp=111 Looks like this one should fit in the rear shelf nicely. Great sale price on this sub right now too. The RMS rating is a bit lower than I would like but anything should be better then the BOSE sub. Any other recommendation on a 10" free air sub that will fit on the rear shelf? Perhaps one that can handle a bit more power. I've never used a free air sub before so I'm hoping this will give the sound system a bit of bass improvement.