If you are not going with a sub, I would make sure that the door speakers are very good quality FULL range speakers that can play down to 60Hz without major distortion..JL or Focal.

As far as placement of the rear tweeters, if I had to do it all over, I would place them in the side instead of the arm rests. They tend to be too pronounced blowing straight up. Guess it's not too big of a deal because I have the rears attenuated quite a bit to preserve the front image. ..Joe

 

Under the front seats for easy access
Under the rear seats for stealth with limited access
In the rear cargo area underneath the false floor
In those storage bins in the rear cargo area...

Ng