with self-financing do you mean that you are going to your own bank to get a loan?
if so, then it functions as a cash sale to Tesla. Your bank gives you a check for the full amount due to Tesla, which should be car price + tax+title+registration. you'll get this $ amount in the final sales agreement. The bank may give you a cashers check with a note that says it's valid up to a specific dollar amount.
Then you pay back your loan to the bank like any other loan. Principal + interest + fees
example final price sheet from Tesla on this post:
You can cheat the TAXMAN.
teslamotorsclub.com