10 Day Payoff Letter from current finance company; Auto Registration Card; Mileage. Mail your payoff to: Wells Fargo Auto PO Box 17900.Denver, CO 80217-0900. Get answers to all your frequently asked questions with MCU. If you're worried about how to get out of debt, here are some things to know — and how to find legitimate help. With Wells Fargo Online, you'll need to complete a one-time enrollment process. You'll need your Social Security number and date of birth to get started. With Wells Fargo Online, you'll need to complete a one-time enrollment process. You'll need your Social Security number and date of birth to get started. Can I payoff my loan online?