I was considering that route too, but it seemed that people sometimes have issues last minute logistics issues with third party lenders--not getting the check in time/not being able to reach customer service/delays/etc.
I figured I'd use Tesla financing at first to handle the process seamlessly, and then refinance later when I'm not stressed about missing the delivery. That being said, if there are fees associated with refinancing or if it's a brutally painful process, I'd consider using DCU from the start. Idk, do people have more insight into this?