I took delivery of a Model 3 LR on Dec 4 in Stockton, CA, and have been waiting since then for the $3750 credit Tesla advertised. I have called them twice (waiting >30 min on hold both times) - once just before the new year and once today - and both times have been told the check is "in processing." It will be a paper check, mailed to the address on the account, not an electronic credit to the bank that you used to pay for the new car. Today, they told me that Tesla did not START processing all of these credits for December deliveries until January and that it would take 6 to 8 weeks for the processing to be completed. So, basically, you may not see that check until the end of February even though you paid for it at the beginning of December!