I thought if you personally were the "guarantor" on the loan it was the same risk to the bank.
I don't know if this link will help but this is how I bought my last truck. They just send you a check made out for $30,$40...K, whatever, and you can use it to buy any vehicle your want. You don't need to "ask their permission." Two or three years ago my rate was about 4%.
http://www.capitalone.com/autoloans/index.php