Why would you do this?... borrow the majority from my 401k hopefully.
You are using logic. My wife hates to owe mony on anything except the mortgage. Sometimes it pays to pick your battles..9% is so cheap you would be losing money to not finance it. So anyone who paid it off and could have gotten that rate is losing investment income on the money. Easy enough to get 2, 3 or even 5% returns safely.