What vehicle?
All of those setups
can work, but from those options I'd choose #3.
You're using the miniDSP 8x12, right?
Are your midbass drivers located in factory lower front door locations?
Generally, the placement in width of the midrange drivers will determine the width boundaries of your soundstage.
So in that regard, the front doors are generally the widest locations and also keep the drivers away from multiple highly reflective and intersecting glass boundaries (see Andy Wehmeyer's recommendations).
If using the top dash locations with both firing into the windshield, I would want the midrange driver pushed as close to the forward base of the windshield, and as close to the base of each Left & Right A-pillar as possible. It looks as if your OEM dash openings are a fair distance away from the base of each A-pillar.
Having the mids tucked into the far forward corners will usually improve the lower end response of the mids due to corner boundary loading and help to minimize the comb filtering & erratic response in the midrange frequencies.
Ideally, I like to keep the midrange & tweeter center-to-center spacing as close as possible, AND on the same plane, with the tweeters oriented vertically above the mids. So in that regard, the Sail Panels would work well and they are usually the next widest position available after the door locations.
With a 2.5" mid and 1" tweeter, it should be possible to keep the Sail Panel pods fairly small and unobstructive. In addition, depending on the relationship to the listening position, IME the bounce/reflection from the side glass can help to add some additional perceived width to the soundstage, though Depth To Stage may be reduced compared to corner dashtop locations.
Another thing to consider. SPL will be somewhat limited when using 2.5" mids, and relatively on-axis sail panel pods will give you slightly more usable SPL compared to dashtop locations where nearly all of the output is distributed over a larger area and is mostly reflected energy.
But with sail panels you'll also have some comb filtering at specific frequencies which will be from the wraparound reflections off of the windshield and/or dash and back to the sail panel pods, as well as from the inner cavity of the instrument panel/guage cluster.
And the combs will also be varied/uneven depending on the frequency regions where both the mid and tweeter are beaming and have narrowed dispersion. Luckily, using the smaller drivers minimizes the beaming points of both.
If the 2.5" mids you are using are the GB25, they hardly need any airspace, so if the sailpanels are sealed they can still be kept very compact.
Placing the 2.5" mids & 1" tweeters in small on-axis dashtop pods that are pushed far forward into the Left & Right dash corners (where your tweeters are located in your photo) can work really well, too. Casey Thorsen, the U.S. Morel distributor & CFO has this setup in his black VW Passat demo car and it works quite well. His tweeters and mids are oriented horizontally, but are as close as possible to each other.
For other opinions, read about
@ErinH's dashtop midrange placement in his newer Honda Civic build log. He refers to a white paper regarding the optimum distance to and angle/sweep of the windshield to the midrange drivers when using dashtop mids. Again, he is using the 4" Esotar2 430 mids that have more output capability than your 2.5" mids will.
Also check with
@bertholomey's Audi build log as he recently switched from his dashtop mids & A-pillar tweeter setup to new locations where both the mids and tweeters were more on-axis and both in the A-pillars/sail panel area. From what he has related to me, it was a good improvement overall.
Personally, I don't care that much for on-axis A-pillar mid & tweeter setups as they are too distracting to my side-to-side and peripheral vision. Even small mids & tweeters create bulges or "bumps" in the A-pillars which are distracting to me, and it's difficult to provide a truly OEM look IMO. If none of that bothers you, it's a worthwhile option.
Off-axis aiming of the mids & tweeters in the A-pillars can minimize the "tumor" effect, but do not work as well IME due to the wildly different on- & off-axis aiming of the Left & Right pillar speakers in relation to your listening position, as well as the difference in the L & R side reflections at your seated position.
It's a compromise (like everything) between the perception of depth & width, to the image focus and L/C/R linearity or even spacing across the soundstage.
Sail panel pods seem to blend in much easier aesthetically since they are just inside of the side view mirrors and tucked somewhat in front of your natural line of sight to the A-pillars.
I like to keep the sail panel pods smooth and simple, and OEM-looking, and blended to the contour of the A-pillars.
I will usually cover them completely with black or color-matched grill cloth so that they blend in without drawing specific attention, and it keeps you and others from being able to see what & how many drivers are being used (confirmation bias).
Just my 0.02
:shruggs: