I haven't read the other posts, but.. If you are having phasing issues in your vehicle, remember these things... 1.) Most of the time, the higher end of the audio spectrum can be heard best when notes generally above 2000 hz are positioned (tweeters) lower in the front door panels. From studies I have read about, you want to keep the tweeter pretty low, without having your legs and other obtrustions in the way of the sound waves. It can be difficult to place your components for the simple fact that a car is so irregularly shaped, and waves have lots of different surfaces to bounce off of. If you can fire the tweeter and midrange directly at your head, while keeping them fairly close to the ground, you will have a better chance of proper imaging. Keep in mind though, that the passenger side door panels will have an awkward angle doing this, as they are farther away from your head than the driver's side. 2.) Also note that speakers in the back of the car will grossly take away from proper phasing. With them still in the back, you will be dealing with major cancellation on select frequencies because the waves from the back and the waves from the front will hit your ear at different points on the sine wave. Thus, cancellation. You can however incorporate lower end notes by placing midbass in the back panel, providing they are filtered to the 100-200 hz range, where the phase problems tend to not be so bad. 3.) Besides the normal problems that people expericence with subwoofer drivers, this will probably be the least of your worries with phasing. Sure, drivers sound the best in one particular spot in the car, but the low end notes don't have as bad of a phasing issue as the higher ones. Hope this helps. Most of this info comes from Geolemon, if anyone remembers him.