[champignon]

There must be someone here who has a 3D printer who could make the critical parts and offer them for sale to fellow forum members!

Addendum: thought of this right after posting. Plastics are ubiquitous materials that unfortunately do not age well in certain circumstances. The two things that reliably destroy plastic are heat and light. The two most important things that you can do to prevent degradation of the plastic parts in your car are to keep it garaged whenever you are not driving it, and not to park it outside in the sun during the warmer parts of the year. The 135i used to be notorious for developing large "bubbles" on the dash, where the plastic would separate from its backing. I doubt that the dash in the 1M is any different from this. All of these problems are related to sun and heat exposure; if you can keep your car out of the sun and especially the combination of heat and sun, you can delay and hopefully avoid these sorts of problems in your car.

This particular problem may be somewhat related to the assembly process, but if you don't have it now, or only have a mild version of it now, do not accelerate the problem by leaving your car parked outside in direct sun and heat.