My MX half shafts (Sept 018 MX Raven) were replaced for the second time last month at the new Delray Beach service center by a tech who has been with Tesla since 2013. My car has 24 K miles, and had the first set replaced at 10k miles. Both times it was due to the dreaded shudder on acceleration. Non-P car. He claimed the answer is coming with the updated cars - that the Plaid (not +) will have a new half shaft design that is backward compatible to our cars that can handle the weight. He said that Tesla's entire problem n this respect is heavy cars, so the MX brought out the problem. I have an issue with this explanation given that I don't drive my MX hard had like I did my former P85D (doesn't even have 'launch'), which never had this, but he says it is because the MX is heavier. I guess that all we can do is wait. Three weeks into the third set, I detect some wobble/shudder already. Poor design.