re: House note vs car note

My opinion (not a financial advisor) you have 6 years left on the mortgage. Which means you have paid mostly interest and have almost all principle left for the remaining 6 years. Assuming a 20-30 year loan term. I wouldn’t pay it off now as the interest savings can’t be much.

I’m also going to assume that in order to get 0% finance the note term is probably short like 36 months so disregard the upside down comment because you will be paying it off so quickly that you won’t be upside down after the first 6 months.
The other poster had the best question. What does this do to your savings? Personally I would take the 0% finance and not pay off the house. And put that 80k into your investments.