This is a license plate display stand. The 5mm holes require self-tapping M6＊1 screws. The upper connection needs M5＊0.8 hex socket screws with nuts. Additionally, a suction cup screw M6*1 is required.

The lower M6 holes can fit most license plate hole diameters for direct fastening, allowing you to hang it on the glass for display.

The lower design also supports quick-release screws.

I don't know if you have such things locally, but at least for displaying Japanese license plates, it is useful. Additionally, the top part can be adjusted to display either inside or outside the glass.

Below is a reference image of the required materials.

The distance can be adjusted both front and back, and it supports multiple angles. If you really want to use it on the car's windshield, the printing material must be changed.