I had been looking at this product for a while; I went and bought it from the store that sells this product and not from Skroutz. It's better if you go to the store in person to take one of your vehicle's license plates so they can measure it and give you the correct product (there are different sizes for some plates). ATTENTION: don't forget to put these little stickers on the plastic in the center (there is a QR code for installation help)

The rear license plate fit perfectly. Now for the front, because my car had a specific spot for screws and it is curved in the front, it looks somewhat like this. I could make two holes to fit it even better in the front. (This is a matter depending on the car). I have had it for over 6 months and none of the plates have come off, and it is extremely stable. I haven't broken any clips (and I take the plates off quite often). I highly recommend it, but for example, the front where my car is not straight looks like this. BUT it can be fixed if I make a few holes in the base of the plate.

Today I received them and tried to install them.
I am afraid I will lose my plates on the road if I install them.
As I read in another comment, the plate needs a little hit to snap in.
I didn't do it because again I can't be sure if they can safely hold the plate.

They leave quite a gap while the plates have specific dimensions. I wonder how difficult it is for a manufacturer to make a support that fits the plate exactly?
And that I have to resort to something new and not cheap (20€) and have to come up with makeshift solutions to install it?

Finally, I would like to add that the silicone addition it has to prevent gaps between the plate and the support so it doesn't move left and right is still not enough to hold the plate.
In my opinion, if I install it, there is a serious risk of losing the plates on the road, and I don't trust them to install it.
The reason for the purchase was to avoid making holes in the new plates.

It was a bit bigger than the sign and needed to be flattened with a hammer (with tape on the tip to avoid scratching the sign) where it has a lip around it. After that, it hooked up normally.

Pay attention to the stickers it has (see photo), put them in the center of the bases so you don't lose them, they are to prevent the sign from sliding left or right (they act like erasers so they don't slip).

Also, the holes it has are different sizes in case you have metal screws instead of those that screw into plastic. I kept the ones that came with the car so I didn't use the others.