neroden
Model S Owner and Frustrated Tesla Fan
I'm still confused. If having the cash is better, why not finance all 70-90k?
The concept is called "emergency fund". It is good to have an "emergency fund" of liquid cash equal to some number of months of expenses in case of sudden disaster (how many months varies according to how conservative you are, and I don't mean conservative in the political sense). *After that* there is no particular reason to have cash, and it's certainly not worth borrowing in order to have more cash than your emergency fund amount.
I have enough cash to buy the car in cash and maintain my emergency fund, so I pay cash.