These are not fonts in the traditional sense where you can just download them digitally to use. The characters are imprints from plate-making dies made specifically for the plate-making machines that produce them.
You will NEVER find a 100% accutare version of this unless you fly over to Switzerland and manage to source and bring back the dies.
That being said, there are a number of typefaces available that either were modeled after or resemble various types of license plates.
A good clone is Numberplate Switzerland | 2000–2004, Stephan Müller, commercial
You can even test it out here. That could solve some of your problems.
It's also worth noting:
Switzerland’s font seems to show multiple influences. Some characters
are based on DIN 1451, such as C, G, O, and Q, which retain DIN’s
circular rounds, while other characters with rounded shapes such as B,
D, P, and R feature more squarish rounds, similar to France or
Britain’s alphabets. Some of the numbers, however, exhibit oval-shaped
curves akin to, but a bit different from, those seen in American
license plates, while the odd zero character with its base wider than
its top recalls the capital O from Germany’s FE Schrift. Definitely a
Here's a German truetype variant that I stumbled across.
Additionally you could just ask the ASTRA Authority, maybe they'd be helpful since "The ASTRA determines the typeface and dimensions for letters and numbers".