We certainly understand how frustrating this situation can be, especially when you've paid up for an innovative, luxury vehicle. However, we should take a step back and look at how far Tesla has come (i.e. multiple production vehicles) in such a short period of time. While it's true that BMW and Mercedes are both much more streamlined, they're also about 100 years old (thanks, Wikipedia).
We can also shed some light on structural repairs on other lower production, luxury vehicles (i.e. Bentley, Aston Martin, Rolls, etc). Certain parts can take weeks to months to arrive. Granted, some of those parts are handmade, but we are factory certified and those are well-established brands.
With the incoming Model 3, our assumption is that there will still be some additional growing pains, but the collision repair process will drastically improve with time.
@pdpspeed Sorry to hear about all the troubles, but hang in there. Hopefully a positive resolution will be formed soon!