Recently ordered the sway bar from Daox and installed it last night. Leaving some thoughts here for any future people considering about this, and maybe other owners who can chime in with some advice:
1. First thing's first: other countries may be different, but if you are driving this car in the United States, you should install this bar. I'm not saying this for "performance" or "road feel," but for safety. From factory this car has far too much body roll for American style driving and speed - it is legitimately unsafe. Either people will rear end you because you will be slowing down too much for maneuvering, or you will lose control trying to keep up with everyone else. Installing this bar will make your Mirage handle like a "regular" car and be much more predictable at regular speeds. I cannot stress this enough. Your life is not worth the $150 you will save by not doing this.
2. My understanding is that there have been some revisions to the design of this bar, with the initial ones not properly clearing brake lines in some cases. Assuming I have the latest revision (Sept. 2020), this is no longer an issue and this sway bar is 100% plug and play.
3. Regarding the two sets of bolts you need to drop into the spring seats to install this bar: you will need to jack up the car to install the two that get dropped into the holes closest to the rear of the car. This is pretty easy, though - just use your factory scissor jack and jack points towards the rear of the car. Do one side at a time. I did this, drop the bolts in, and then took the car for a spin around the block real quick to settle the torsion bar back to a neutral state.
4. Tightening the nuts onto the bolts holding the sway bar in place is at once the most important and most ball-achingly brutal part of the install. The bolts are sitting on smooth washers in the spring seat, and the nuts that Daox supplies with the kit are good ones with a nylon locking seal on them, making them resist tightening. The result is that the bolt will just spin in place if you try tightening the nut down without simultaneously, very strongly gripping the head of the bolt. This is complicated by the lip of the spring seat and the spring itself being in your way, as well as being unable to jack up the car for fear of screwing up the resting position of the torsion bar. I was able to (with the use of much profanity) grip the head of the bolts with an adjustable wrench while tightening the nuts down, but it was extremely difficult, and I do not think I was able to tighten things down enough. I need to go crawling under the car again tonight for round 2, as loose bolts seem to result in "clanking" coming from the rear end, which I've heard a couple of times during my test drives. Any advice from other members on how to reliably tighten down the nuts (at least to the point that I can reliably grip a torque wrench with both hands while doing it) is greatly appreciated!
5. Having this seat bar installed does not increase the noise coming from your rear end. As others in this thread have pointed out, if you are hearing new clanks and groans after installing this bar, you have not tightened down the bolts enough. I was able to get the rear-most bolts to 70ft-lbs, and the front most bolts to 35ft-lbs (tightening the front ones is extremely difficult and I would have got them to 70ft-lbs as well, if I could), and this was enough to keep the rear end quiet and happy.
6. This does not result in a harsher ride, at least as far as my butt can tell. You're still on super soft shocks and springs, and adding this bar won't do anything to change that. The only thing this bar seems to do is virtually eliminate the egregious body roll this car has from factory - and that's a good thing.
So, in conclusion, thumbs up to Daox on a great, affordable product that works as advertised and will save lives. If any members have advice on tightening those bolts, I'd love to hear it!