Our 2013 P85 with 31k miles just had the drive unit fail. We had experienced the "clunk" when lifting off acceleration before regen started; our SC was contacted and a 'fix' employed that took care of it. We were not informed of what the fix was. The "droning" at speed >60 began to get more noticeable since but there was no milling sound, as demonstrated on TMC anyhow. The milling I listened to posted to Soundcloud really did sound sort of like cicadas in its variation, pitch and when it occured was not like our droning sound. Last night, wife driving home at 11pm and heard a thunk in the rear, then a clear drive unit fail. 1 hour for the flatbed but Tesla service knew on the phone right away what it was as did I. I spoke to the service center in PDX today (who happened to have a DU on hand) and asked a few questions: 1. You have been replacing a lot of drive units, it seems like mostly for some abnormal sounds and not drive failures? A: Correct, failures are rare. We are being preventive in replacing them. 1. Which sound is the one to worry about, when do we call them? A: (not clear) call anytime and will have a technician ride along and send any concerns to engineering. 2. What changes are made to deal with the clunk, the drone or the milling? What revisions have been made? A: I don't know and we'd have to get an engineer to help us answer that question. 2b: Can I? A: Um, well, not at this er...we will know more soon. We are a new company and constantly improving. 3. Should I worry every 30k miles? How about after the warranty is up? A: We don't know and are a new company and constantly improving. You are under warranty for now. 4. Is this a refurb DU and which revision is this, A-M? A: It is a refurb, and it is "version "P". 5. If we were to trade in our car, should we get a dual motor or avoid a P? A: The duals are too new to know. We have been replacing both standard and Ps. 6. Is this same DU revision in the Model X? A: We don't know at this time, as a service center we don't have all the specs. We will start seeing them soon and will then know but I expect they will be the same for the large DU. Overall, they are very nice about this but...they have been well coached in responses. They seem to be all over the DU replacement issue, so it must not be rare even if actual failures are. I think others on the forum have had great speculation about the sounds not coming from just one thing and that one? plus the failures are due to unexpected wear occurring in the differential/transaxle. It seems like the use and complexity of an induction motor instead of brushless is perhaps the reason for their success but also this issue. I can see this going one of two ways, and neither will we know up front. There is too much for them to lose to be transparent. 1. Engineering fixable: They are on revision P...they are learning from each replacement and refining for long-life drive units. Their earlier efforts in cars with 3-4 replacements will become rare due to what they have learned and improvements made. They will be more and more transparent and explanatory about the issue. or 2. More complicated than they can handle: These are the basis for all Model S and X, if not their business secret sauce on top of their battery. Thus they have to string everyone along as they grasp at straws and keep seeing issues providing as little information to owners/public as possible. This worries me in regards to their solvency and long-term plan. I'm concerned their actions sort of reflect crisis management?