If you need someone to co-sign your loan, that must mean that you don't make enough to pay for the car. Upset or not, maybe you should listen to what the writing on the wall is saying.
Either make more money yourself to be approved, or wait until a time in your life when you do. Why not go for a 335?
Making better financial decisions now (when you are 20) will lead you to better chances of continuing to own good cars throughout your life. Overextending yourself now might not be the best thing.
I hope you also own a house if you are talking about purchasing an 80k car, BTW.