I thought I would share my experience. Maybe it will help someone else.
I have an early sequence number, finalized and signed pre-MVPA in mid January. My order has been delayed because I selected red which has not yet gone into production. I saw the letter about the 3rd row seats from Tesla on the forums first, but I did eventually receive the email directly, albeit 12+ hours later on 2/28. I sent an email to BuildMyModelS@ immediately, and asked if adding the 3rd row now would 1) Change my delivery date in any way 2) Cause an increase in base price. After sending the email, I realized that 3/1 was the next day and that it was possible red could enter production in 24 hours (unlikely, but possible.) So I called. The first person I spoke with, while helpful, wasn't up to speed on the email notice that was sent. I read the letter from Tesla over the phone to this individual. He put me on hold a few times to check with other people, and then asked if he could call me back.
He called me back about 6 hours later, and said that I could add the third row to my car, and that it would not change my delivery schedule or pricing, but I would need to sign a new pre-MVPA. At this point I asked for the 3rd row to be added. Within minutes I received an email stating my pre-MVPA paperwork was being generated. Here is where it got a bit odd. On Friday morning I was on a flight for 5 hours. When I landed, I was expecting an email requesting that I sign the new paperwork. Instead, I received a generic email that said that while I had configured my car, that I had not finished the ordering process and I needed to FINALIZE! From the airport I logged into the website, and sure enough, I was back at the pre-finalize stage. I added the 3rd row option myself, finalized, and once again received an email that my paperwork was being prepared.
I followed up with a phone call, now very nervous that I may have lost my position in line (it's still not clear the order of operations between sequence number and date finalized.) The rep I spoke with confirmed they were preparing my paperwork, and did not seem concerned that my order had been brought back all the way to pre-finalize, or that I had received conflicting emails (first the preparing paperwork, then the you need to finalize, and then preparing paperwork for the 3rd time.)
My guess is that it was easier to send my order back to the pre-finalize stage and have it follow the normal workflow then for them to manually add the 3rd row and generate new paperwork. Again, total guess on my part. I wasn't thrilled that one thing was communicated to me and then a different course of action taken. Had I not been watching everything like a hawk I could have easily found myself with a delayed or screwed up order. It might still happen, I suppose. At the time of this writing (3/3) I still have not received the paperwork, but the email says up to 1 business day. Hopefully it shows up on Monday, or I will be calling again.
Update: I received the revised paperwork and it was counter-signed on 3/4. I spoke with a Tesla rep who confirmed the revised order was complete, but then told me she thought my order might be delayed by a week because of the change. If it's really just a week I'll live, but it is another data point that Tesla is doing a very poor job with communications. All the previous individuals I spoke with said it would not have any effect on delivery time (IE, I'd keep my place in line.)
