I've actually been doing the same thing myself. I have a FG so it's a little bit different.
Been doing the requisite reading on DIYMA... I'm a big dude so doing kicks just isn't going to work... too much of me in the way, so stock locations on the doors for the mids... but the tweets are another story entirely.
Came across this, which is a repost of another post from Rick at RAAM Audio.
For those not building kicks here is a simple install plan that works quite well, has been used alot in competion cars.
1) use the door locations for the midbasses, both in phase.
2) tweeters in the A pillars firing directly at each other, as wide apart as possible, both at the same exact height and about 2" above the highest point on the dash. Wire both tweeters out of phase(pos and neg wires reversed but this may have to be reconsideded depending on the midbass wiring, take your timem and try them all! Make sure to try many different aim points as well.
3) Use a dash mat, fugly but they work.
In fact, a dash mat will improve just about any install ever done, including kick panels, have one in my truck, been there for years"
There are other methods of course but these two are the easiest to implement well. The kick version is slightly off axis on purpose, the A pillar tweeter version is way off axis and very easy to get great results from.
Here's a link to the full thread, I just copied the part that was most applicable.:
where to 'aim' a-pillar tweeters? - Diy Mobile Audio - The Ultimate In Sound Quality
Now based on this advise, it would seem the best position would be like so (or maybe about an inch higher):
With the rake of our windshield... and the irregular instrument pod shape, is this still effective?