It's a farily small output, I'm estimating at 10w RMS (which equates to probably about 40w Peak to peak, amp manufacturure use inflated numbers these days). I replaced my head unit and looked at putting a more powerful subwoofer in, but your hole diameter in the back window is about 6 3/4" and all of the subwoofers I looked at were 7" or greater, and I didn't want to cut sheetmetal in such a beautiful car. I might want to restore it to stock someday.
Also, the mount to the subwoofer is a stepped mount, you would probably have to fashion custom hold-downs for the 4 mounting points for the speaker. After all of the trouble pulling XM radio cables through the car, I just didn't want to do any additional work.
Hope this helps. Let us know what you decide and how it works out.
KCB
