You currently have two car notes? And you want a third? And you're thinking you'll put $15K down on (what you hope is) a $30K car?
Credit is all about debt/income ratio, with a smattering of assets thrown in. If you're thinking you can afford to spend $15K out of a savings of, say $40 or $50K on this car, with no other debts, if you're gainfully employed and your total debt/income ratio is 'ok,' you can always find someone to lend you the money.
If you're looking at that $15K being all or most of your liquid income, you will be instantly car poor, 'upside down' in your car the minute you drive it away from the seller, and will not be in a happy place financially.
Oh...and you MUST shop insurance before you do this. At your age that will be a very significant element of your figuring out if you can afford this.
All very good points.
I would add that Chase likes to hold car notes to no greater than 70% of an individuals income except for rare circumstances. Example. An individual makes $100,000.00 a year. Chase would like to see the vehicle note not exceed $70,000.00.