It sounds quite good at normal volumes and I use it at max, it sounds fine there too

The Cento series truly has something extra in terms of purity and naturalness of sound. The difference compared to similar-priced series is enormous.
However, be careful, these coaxial speakers have such a linear response up to high frequencies that they are definitely not suitable for use in combination with factory tweeters. It is not something that can be corrected with EQ.
If you also have tweeters, you need the C 165, not the CX. And if the CX speakers are installed in the rear where there may have been a woofer without a tweeter, the overall cabin changes noticeably. In my case (Lancia Delta 844), it changed for the better, but in other cases, the result may be excessive, and it definitely alters the stereo imaging, which takes time to get used to.
Also, a factory source of the 4x25 type is not enough to fully utilize them, although the sound is powerful. From the midrange and onwards, they lose quite a bit, and the loss starts from low frequencies, making the bass even poorer. Approaching the maximum volume, the "clipping" is very noticeable.
They are not expensive for what they are, but I give them 4 stars for the poor packaging that resembles mishandling of a used product, and for the fact that in such expensive speakers, cables or at least connectors are not included, while they are included in speakers of the 20-euro range.
The 4 stars also take into account that in most cases, they are not sufficient to improve the sound on their own; on the contrary, the result may be worse. The notion of "I will buy 2 good speakers and the sound will improve" does not apply at all. You need to know what you're doing, upgrade the other speakers as well, and most likely the source as well. Adding up all these factors, with cables, mounts, and whatever else is needed, the seemingly acceptable amount of ≃100 that they cost is a small percentage of the total that will be needed.

I replaced the factory speakers of my Peugeot 307 SW in the front doors with these specific ones. It's like day and night. They make a lot of noise with the factory radio. And the bass is amazing too!

Purchase 105e
Wonderful speaker, enjoyable.
Distinguished for its atmospheric, three-dimensional sound.
Very good mid and high range. Sufficiently deep bass.
Very good resolution, marvelous tones - 'silk-like'.
I placed them behind and put foldable ones in front. I regretted it. I would have preferred to have four of these.

I installed them in a Peugeot 207 3d, they didn't fit directly because the hole was smaller, so I added an extension and everything was fine. In terms of sound, I'm using them with a JBL 60 rms per channel at 4Ω, they play very well and clean without distortion, but I have reduced the bass (not completely) because I have a subwoofer

(Purchased a little under €90)
Crystal-clear highs, decent mids, and honest bass.
With a Pioneer 4x50w source, the result more than satisfies me!
Finally, the big advantage is that they can handle amplification for more demanding use.
Much superior to the DSK165.3 component speakers!
(Installed in a two-seater car with a small cabin)

Update after 3 months of use, playing sound exclusively with this pair of coaxial speakers, without a sub, amplifier, etc.:
Even with the roof open at low speeds, of course, the mids and highs sound wonderful. If you want to listen at higher volumes, a bit of low-frequency crossover through the source might be needed (50-63Hz). Among the best speakers I've bought, I continue to recommend them to anyone who wants something good.