Audio Systems: Speakers, bose amp, bose speakers

Question
I recently installed two new speakers in my Acura and A pioneer remote Cd player yet my front bose speakers play well and my rear replacements sound as though there not reaching a full potential, the rear speakers are Acoustic power 250watt 6x9's. I also wanted to know if My system needed an amp to get that sound potential.

Answer
this is my guess of what's happening here:
your acura has a bose system which already comes with an amplifier inside the car somewhere (usually a black box under a seat or up under the dash somewhere)  this amp is designed to put out it's power at the load the bose speakers were which to my understanding may be as low as 1 ohm.  the new speaekrs you put in are 4 ohm speakers which going from 1 ohm to 4 ohms would draw about 1/2 to 1/4 the power and thusly be 1/2 to 1/4 the volume.
so if the amp was rated for 60 watts at 1 ohm it may only put out 15 watts to the new 4 ohm power acoustik speakers.
to tell you the truth your rear speakers should be much quieter than the fronts anyway so technically I would leave it alone.  having the rears up to the same volume will ruine the effect of a front focused sound stage.  also 6x9s are notorious for sounding distorted, muddy, and create very localizable midbass that draws your attention to the rear of the car which again wrecks your front sound stage.  Bose systems are very difficult to adapt amplifiers into becuase of the above mentioned ohms of the speakers and the fact that there's already the bose amp in there, my recomendation to most people that want to upgrade is rip everything out!  the speakers, the wires, the amp, the cd player, and start over,  I've helped many people do this and if you're interested I'd be happy to help you as well.  let me know what you want to do.