i was wondering about the diff between the stereos on the pro and the pro5, seems to me that the pro system would sound a bit better cause it has the larger speakers in the back and they are mounted on a fixed object, not a door. and as for the tweeters up front, my dad's car has them and i don't think they make that much of a difference

 

There are some advantages of each and it depend on you r own bias.
The rear speakers in the Pro sedan are nice becuase they are high and if faded to the front they can greatly help the level of the sound stage. The problem with them is they are so damn loud that they over power the fronts and put the sound stage behind you. This is ofcoarse the worst sin in SQ listening. Now the P5 benifits from having a smaller speaker to lessen the pull to the rear of the car but you can't use them to rasie the sound stage either.

I like the location better on the sedan but i don't use 6x9s either since they play too low to help the sound stage. I replaced mine with 5.25" mid drivers only playing 300hz-3000hz when i actualy have them hooked up.