While I won't claim to have gotten lowest rock bottom deal on every vehicle I have purchased I am at the same time 100% certain that any "excess" I paid was lower than the normal cost of borrowing via a LOC, and a fraction of normal bank car loans not to mention my portfolio return.

As to the chances of defaulting on the loans lets just say you probably should worry more about the general state of the economy.  If my portfolio fails to that extent it means pretty much most of the nations major companies have also failed.    I suspect the same is true for Bankish.