I couldn't find where I had posted this but I have had a couple questions lately so I figured I would post the info again.
I replaced the factory speakers and subwoofer. Very minor mods to make it all fit. Also added polyfill to the areas around and behind the speakers which helped. The last thing I would consider, but didn't do, was get an Alpine 5 channel amp to drive it all. I am just using the factory head unit and cheesy little factory amp for the sub. I used Polks for the dash and pod speakers, with the 33 Engineering adapter plate to fit 5.25's in the dash.
Subwoofer = Pyramid PW677X from http://www.teptronics.com/pw677.html
Front Speakers = Polk Audio db 521 5.25's from http://www.crutchfield.com/p_1…lk-Audio-db521.html?tp=97
Pod Speakers = Polk Audio db 651 from http://www.crutchfield.com/p_1…lk-Audio-db651.html?tp=95
Crutchfield had a buy 1 at full price, get second one 50% off so it was only around $150 for all 4 Polks... Sub is only like $8. Bang for the buck was huge and I think they sound great. Vast improvement over even the Rubi system.
The amp I was considering was an Alpine PDX-5 from http://www.crutchfield.com/p_5…/Alpine-PDX-5.html?tp=115. But, not worth it to me right now. 