Hello & Welcome to the forum! It's hard enough to get any loan these days & with 12K neg equity.... very highly unlikely. Did you get a second opinion on the repair for you car? I can't imagine a repair running 6K even for a new engine. I'm not going to say I don't believe you but I would call other mechanic shops before jumping into a loan thats 12K neg.... the payment would be outrageous! Also, I haven't seen a bank that will finance more than MSRP on an auto loan. If you can afford it... maybe buy a used auto until you get on your feet?