has anyone done this? if so how'd you do it? i just want to be able to bump it a lil more

 

Get an amp that takes speaker wires as an imput. Run some wires off of your rear speakers and use those for your inputs. Then just run the power wires for your amp. If you want just a little more bump get one ten with some descent wattage.
If you want better sound though, get a head unit too. That way you can use a sub output which sounds like a hundred times better.

 

you just solved my dilema too

 

You want to get the speaker line inputs from the Bose woofer, not from the rear speakers. The way the stock Bose system is designed there is a crossover built into the amp. You will get better bass off the woofer unit (take it apart and you can access the red/green wires on the back of the speaker).