Buying a car.. anything wrong with this plan?

I'm 19 and I need to know if this is a stupid idea. Right now I have a Hyundai elantra that I bought a few months for around $6500 and it has 100,000 miles on it. It's completely paid off. I don't have to pay for tuition because my dad will handle that, and I even have around $20,000 saved up for if I

I'm 19 and I need to know if this is a stupid idea. Right now I have a Hyundai elantra that I bought a few months for around $6500 and it has 100,000 miles on it. It's completely paid off. I don't have to pay for tuition because my dad will handle that, and I even have around $20,000 saved up for if I ever need it for education. My mom offered to take care of my rent, which is $400 a month. I want to save up a bit more money for a down payment on a Mustang (most likely) that costs $15,000. I have really good credit and can easily get a car loan from the bank and I already looked at insurance rates and all. Without speaking to an agent first it comes to around $250, plus the monthly payment which will be $150. Since my dad and mom are taking care of other things, Im wondering what's wrong with this. I really, really want this car. I don;'t mind having payments for it, Im a huge car enthusiast and Im pretty crazy about them lol. I was thinking if I had this new car (with lower miles and all) I can sell my old one. Be honest with me, if I could afford it is there anything wrong with this? I work two jobs as well so I make more than enough to get by with my parents helping me out. Thanks.
Oh and the reason I went with the Elantra was because I was living with my dad at the time and he would not let me get a different car. I feel I shouldve been able to since it was all my money.. I just needed a new car though so I didnt push it much. I've been living on my own though so I can do whatever now

Other answer:

Been There, Done That.:
Your dad's not real knowledgeable when it comes to car quality, so stop listening to HIM LOL.

Look, you're young and single. THIS is the time to do this plan, as the day will come when you'll be trying to raise a family and there will be NO extra money to buy things YOU want.

This was the mistake I made. Got married at age 19 and started a family. Only NOW, that I'm in my 70's can I buy any car I desire. A new Corvette is on my bucket list for this year, but I sure could have enjoyed it a lot more if I was in say, my 30's. (Or your age)

Peter H:
Could you afford to take over the $400 rent payment from your mother? If you can, then I would say yes, you have got yourself sorted, you can afford to indulge yourself. If not, then take a hard look at yourself. You are only 19, you are not self-supporting, you don't appear to have set yourself down for higher education. What is your earning power going to be in the next 5-10 years? Will you be able to finance getting married and starting a family.
Indulge you enthusiasms only when you can afford them, I say.
Dan B:
From your posting, the MAJOR problem is that your income will not support the payments. It doesn't matter if anyone else is paying your bills. Income from mom and dad is not guaranteed or proven or contracted. Neither is income from a job but it has more status. Lenders want to see YOUR ability to make the payments. Your parents would effectively be giving you an allowance, not income.
Barry:
You said your "mom and dad are taking care of other things." To me, that means that even though you are living on your own, you are not really on your own and still have to answer to your father. If he disapproves of you buying a Mustang, might he be less willing to "take care of other things?" Might be conclude that anyone who can afford that kind of discretionary spending does not need his help?

Personally I would drive the older car as long as it is reliable and conserve the cash. Until you are working full time, you never know what you might need that nestegg for.