Soundstage issue with components

I recently installed a set of CDT EF-61 components in my '96 Camry.  At first, I the sound/imaging was little off, but I did a lot of reading on this forum to determine that the most likely problem was my own doing.  Initially I had the tweeters in factory door locations which was less than stellar.  Then I moved them and pointed them directly at the driver side so that I was hearing them on-axis, but this was way too coming right at me.  In the end, through much experimenation, I've got them just where I want them (I think) angled slightly up and toward my rearview mirror.  This seems to be an ideal direction for my car.  These components now sound better than anything I've ever had.  The soundstage is right out front where I like it, and everything is clean and smooth.  Now for my question....

The only slight issue (I may be too picky on this) is that as you near the edge of the soundstage towards the doors the stage drops off down to the tweeters fairly quickly (the tweeters are mounted about 6" from the mids so they may be a bit low on the doors).  I guess the best way I can describe what I hear is that it's kind of like envisioning the soundstage as the top of a trapezoid....smooth line nearly all the way across and then quick drop down at the ends.  I'm not sure if this is clear or not, but to fine-tune things, I was toying with the idea of adding CDT imaging tweeters on the sail panels to bring the soundstage up all the way across.  I've never used imaging tweeters before, and was just wondering if this a good idea and is this the type of issue that imaging tweeters are supposed to be used for?  Since I've already got most of the stage where I want it, I don't want to monkey it up too much, but the imaging tweeters seems like a good idea.  Then again, I've had "good" ideas before that went south quickly.  Thanks for any experienced opinions.