Slim powered sub to replace cab woofer

[Gruntis]

What are peoples thoughts on swapping out the cab woofer for one of these to get a bit more base - http://www.fusionentertainment.com/car/products/active-enclosures-cp-series/cp-8-Super-Slim-Active-Subwoofer
Given its dimensions it should fit.

Would it be as simple as finding 12v to power the amp and hooking it up to the wires going to the original? Or more to it? Or simply wouldn't work/not worth it?

Thoughts??

[TUF-427]

I use these from Jaycar under $40. Run ok from standard sound board..
Most Car amps need a Pre Out signal level for the input,
The level from the sound board will prob damage the Amp.
You can get a pre out level converter and some amps do have a high level input but not many designed for car audio..
Many home theatre Subs have high level inputs u can just run the cab speaker wires  to those