As promised, I'm coming back now after having this sunroof installed for a few days to give a brief review of it, and maybe provide some comments for anyone interested in doing something similar in the future.
Before I begin, if you are interested in doing something similar, you will need to do it soon. To the best of my knowledge, all of the aftermarket sunroof manufacturers in the United States (as of Jan 2021, at least) have already completely ceased production of any models for sale to the aftermarket. There is probably a good reason for this (I will mention later), but what it means for you is that parts availability will be zero in the future, and is already approaching that point now. In the case of our Mirage, I was informed that only one model from Webasto would actually fit properly - the Hollandia 321M.
What I Had Done
The model of sunroof I had installed on my car was a Webasto Hollandia 321L. You will notice that is different from the 321M which I specifically called out above. The difference between the two is that the "M" stands for medium, and "L" stands for large. On my original receipt they had listed the 321M, but during the install a month later the shop I had gone to told me it would be the 321L. I didn't really ask why there was a change. My guess is they were unable to actually find any 321M's in the wild, didn't want to lose my business, and decided to gamble with getting a 321L to fit. It all seemed to work out fine in the end, though, and I'm certainly not one to complain about getting more for my money.
Speaking of money, the total cost for the parts plus install was $1.4K, before tax. Compared to the original cost of the car, it's a lot, and you're essentially gambling that you will get good quality of service on installing a non-reversible modification to your car. As such, I really wouldn't recommend this to anyone with even a minimum amount of financial responsibility/obligations. In my case, though, I'm young, single, have no debt, and earn a decent wage, so it was a "I'll do it because I can" kind of decision.
Results
They say a picture is worth a thousand words, so here are several:
My Thoughts
In all, I have come away pleased with the modification. It is, indeed, a hole in my roof covered with glass. The electronic controls work very well, and the sunroof even has a built in function s.t. it will close itself after you turn off the car if you leave it open by accident. There are a few "gotcha's" that you should be aware of, though:
First, our car is very small, and Mitsubishi has gone to great lengths to make it very aerodynamic. The result is that at pretty much any point you pick on our roof, it actually curves away from that point in all 4 directions - to the front, back, and to each side. We're essentially driving little bubble boy cars. While the sunroof itself is likely slightly curved to begin with, its curve does not (and cannot be expected to) perfectly match that of our car. The result is that the curvature of the roof needs to be adjusted in order for there to be a proper seal. The shop did a good job on mine, but if you are a perfectionist like me you will need to be able to deal with the reflections off your roof no longer being smooth. The warped/stressed points will be very visible if you are looking for them. Our roof is also wider at the front than it is at the back, so if you look at the car from one of the front corners, it gives the illusion that the sunroof is installed crooked.
Second, this sunroof actually sticks out slightly above the top of the roof when installed, even when closed. This likely increases aerodynamic drag, which may or may not be acutely felt on our vehicle which was designed so tightly around minimizing it. This is hard for me to really test as there are so many factors that affect MPG, and also because I have a grand total of a 2 mile commute to work. Nothing obvious seems to have cropped up yet, though. I will post back here if anything changes in that regard.
Third, you will lose a little bit of headroom. It's not much, and the interior of the Mirage still ends up feeling large, but if you were somehow headbutting the ceiling on the regular before, it may get worse afterwards.
Nitpicking
The control buttons on the inside of the sunroof glow green instead of orange like the rest of our car.
The built-in shade is essentially useless. It is a fabric roll instead of a hard plastic piece. This was done in order to keep to overall dimensions of the unit down. Unfortunately, the fabric is so thin that the sun continues to shine through it even when closed. Additionally, the glass is already strongly tinted s.t. it doesn't let ~90% of UV or heat into the vehicle. Because of all this, I will be removing the shade, if possible, as the only purpose it really serves at the moment is to get in the way occasionally.
Webasto's trim plastic is very hard and comes with a decent number of burs still attached. Nothing a little time and patience can't solve, though.
Would I Recommend?
Meh. Probably not.
The main reason I end up feeling this way is because (in addition to the cost and gambling, as described earlier), it turns out that my Mirage is a victim of its own success. The car is already so small, with such an open interior, with such large windows, that the sunroof really hasn't impacted the amount of light entering the cabin at all - which was my goal to begin with. So, in pursuit of that goal, it is an unimpactful modification. But it's an interesting conversation piece, I suppose.