So if you want the guaranteed resale value guarantee, Tesla's banks (Chase and TD) will want 10% down plus your sales tax. Of course your $2500 deposit goes towards that, but don't let your jaw drop when you hear the initial number quoted, which will be around 16-20% of the sticker price of the car depending on where you live.
Note that TD allowed placing 0% down, but that raised the quoted interest rate by over 33% which wasn't worth it to me. I know the 3rd party credit unions often let you put less down, which might be more attractive if you come from other car loans where it's not necessary to make a substantial downpayment.
BTW, I really wish Tesla were more up front about this instead of telling you the real number during the financing stage. The configurator said $4400 due at signing (or $8500 down with GRV), but by the time I got the finance guy quote, the number was $16,000 not including the $2500 down. I don't mind paying a downpayment, and fortunately there's still enough time after getting the quote to the time where I'd need to pay it for me to move cash around.