Hey Treystoys:
I started my sound system with the exact same upgrade (i.e. replaced the stock speakers with pioneers all the way around). I agree with what you said about the improvement. I then wen the next step and added a 4 channel 640 watt Kenwood amp and a 10" Power Acoustick sub in a...
I'm modding an automatic (with sportshift) P5 too. Granted that the increases in HP aren't as direct as with a manual, but there still is a difference, particulary when it's in manual mode.