Check out a thread called "speakers in rear deck" in this forum from a few weeks ago.
A few people have done this. Major complaints include tons of rattling, plus having the sun beat down on your speakers isn't so great for them. You'd have to cover the speakers somehow.
Upside includes more storage room in the trunk. Plus -- if you have the sub in the car, you only need one, so you could probably sell the two you have and buy the one you'd want without having to shell out much except for whatever they charge to do the install.
Also -- on the passenger side of the rear deck there is a hole about 6.5 inches diameter. People have mounted 8" woofers to MDF, then the MDF to the rear deck, creating a 'spacer'.
Apparently the sound is not quite as boomy as twin woofers, but the bass is right there where you want it.
Brian
