P85ATL:
I own a 2015 P90D. I base my comments on the history I've experienced, not what I've read. Here goes.
When the car was a few months old, the main 90Kw battery was found to be defective, but they wouldn't simply replace it. Despite my repeated requests, they said that was not how Tesla did it. They said it had to be shipped back to CA and be "re-manufactured" and they installed a loaner battery. Estimated time was 4 - 6 weeks "depending on how backed-up the remanufacturing process is".
It arrived 6 months later.
When installed back in my car and diagnostics run, it was found to be defective, it could not hold a charge. They hadn't run diagnostics before sending it back. It took another month and the people at the SC acting as my advocates arguing with the people at Tesla HQ, but they finally got their policy overturned and agreed to install a new 90Kw battery. I know for a fact that it's a new battery as the design had changed and to put a new battery into an older car required an adapter kit. They failed to send that kit with the battery, so there was a further delay.
So, fast forward to more recent time. Around Thanksgiving we had family visiting from Houston, and they wanted to go for a ride in the Tesla, so I went into the garage to get the car out. The drivers door handle would not extend. All the others worked. So I had to open the passengers door and go feet first over the center console to get into the drivers seat and take the car to Tesla. When I got notice that the replacement door handle was installed, I went to get the car. As I was signing off on the paperwork, the service person said "Your car was one of 5 that we replaced handles on today". Great. TMI.
A month later the airbag warning light came on. I called Tesla, and they said to get the car to them asap. They later explained that when that symbol is on, the entire airbag system is shut down. They found that the airbag's wiring harness had failed and they ordered a replacement. When it arrived, there was a problem. The harness that arrived was the correct part number, but it was the wrong harness, and it wouldn't connect. This took a couple of weeks for them to figure out and with Christmas and New Years happening, I was in a brand new loaner car for a number of weeks.
While driving that loaner, I noticed that the heated seat cushion was significantly hotter than the one in my car, and as I thought about it, I couldn't ever remember feeling much heat from the cushion. When I turned the loaner car in I asked if they had upgraded the heated seats, or could my car have a problem. They checked and said that the heated seat in my car was defective. To correct the problem they couldn't just replace the heating element, or just replace the seat cushion, but rather they had to replace the entire drivers seat. When I heard that I said "OMG -- how much would that cost if it wasn't under warranty?" The service person said "I don't know -- all the ones we've replaced have been under warranty". The important words there are "all the ones". I asked how long it would take to get a replacement and they said 4 to 6 weeks.
Realize that was in early January. We now are at the end of March, and the seat has yet to appear. And, from when my car was built and now, the stitching pattern on the seats is different. And, my car has a gray interior, and Tesla stopped making gray interiors last year, so I have no idea what's going to show up. But that's not my problem. While my lease doesn't finish until the end of September, I'm dumping it, making a large lump sum payment to pay the remaining months, and turning it in next week.
I've driven S class Mercedes for the last 20 years. I know how they treat their customers. When I spend $120,000 for a Tesla, I shouldn't have to put up with all these problems, complications and delays. Owning the Tesla was fun at first, but no more. I'm going back to Mercedes.