I left my order with Tesla as cash, until I was ready to rate match.
With DCU I became a member and applied for the auto loan a few weeks before I had a VIN. Once you get your VIN you need the MVPA from Tesla to upload to DCU. Then I immediately called DCU (2 hour wait) and they finalized the loan application and emailed me the official documents the following morning. I then sent the DCU loan docs to
[email protected] and they matched the 1.24% at 72 months (you have to ask for the 72 months otherwise they will match DCU's 65 months).
It sounds like a big process but it really wasn't so bad. I recommend getting the ball rolling ASAP with the DCU membership/account and initial loan application.