Personally, I am not a huge fan of rear fill speakers. A properly designed system will not necessarily benefit from them...unless you have a 5.1 processor or something like that. For straight-up SOUND QUALITY, you might find that you do not need them.

At a concert, all the mucicians are infront of you....none behind you...why put speakers there?

D5 or D7 amps? I think you would be perfectly happy with the D5 line....great stuff. If you are the SQ snob that I am, then D7 (or D9) all the way. I think the savings on the D5 line might be better spent on other upgrades. Better cables, Dynamat, nicer install, and the like.

I am not sure if you will need a second battery...just make sure the one you have is in good condition. If its over 3-4 years old, you might wanna think about a new one. A second battery will give you longer engine-off play time, and make your alternator work harder. If you go with D7 or D9 amps, then YES, you will probably need a larger alternator.

You might want to think about 1 of 2 set-ups.

1) a set of 6.5 components for the doors. Place the tweet in the factory door spot, and a second set of components (5.25 or 4") in the kick panels. Use the 4-channel amp to power them.

2) a 3-way set up up front. 6.5 in the door for midbass, and 5.25 or 4" components in the kick panel for mid-range and highs. Again, the 4-channel amp. Channels 1-2 for the mid/highs, and channels 3-4 for the midbass.

#2 is essentially what I have in my car. 5.25 hex components in the kick panels off a D7152, and a set of 8" midbass off another D7152

John