Well, there is a way to make almost any tyre size legal. It's called "LTA" and roughly translated, "Automobile Technology Laboratory".
We go there with the size we want to make legal and they test the car. If it doesnt scrape the body and if it doesnt go off the limits of the car, they will issue a paper and then we can go make it "street-legal" in the car registration.
When we get the size we want (150€ test + 40€ burocratic) we can then find a large set of wheels with the right offset and mount the tyre size on it
Nowadays, i still drive illegal with 195/45r16 but i want to go to LTA and legalize 195/40r16 front and 195/45r16 rear. I just need stock r16 wheels because the Borbet's stick outside the car