I think it is safe to say the "Estimated Delivery" is a joke. I put my order in this morning and added my insurance card for my explorer and about an hour later my Estimated Delivery date says February 1st - February 12th.
At least for us, when the delivery range first appeared (previously showing no estimate at all), it has been accurate so far although the earliest date of the range is probably unreasonably(?) set to "today."
Early January 31st: January 31 - February 16
Late January 31st: January 31 - February 06
Early February 1st: February 01 - February 06
Scheduling options on February 1st only allowed 2 days: February 05 or February 06
Separately, if people are considering timing of payments to potentially make partial payments from multiple accounts. Here's my experience with Fidelity:
T+0:00 Requested online wire transfer (no place to put a memo "name, RN#", but destination account includes RN#)
T+0:30 Received bank email "disbursement in progress"
T+0:34 Received bank email "disbursement successful"
T+0:40 Tesla account reflects payment
T+1:07 Tesla email "cash balance update"
So in this case, probably at least a 40 minute delay from requesting to reflecting wire payment. Whereas it sounds like if you complete final payment with Plaid (apparently no way to manually enter in routing/account number nor partial payments anymore), using the web interface will reflect it as paid immediately even though it'll take a few days to complete. At least for us, the final payment is now low enough that it can be completed from multiple accounts if we need to go "enter your bank credentials into Plaid" route.