I am having car finance problems?

i am 20 years old and i am in airforce, i was just wondering if i am getting a good deal and what i should do about this...i got approved 15k loan from my bank. at 7%APR...ik its high, but its because of my credit score just getting started...i have been car shopping for about 5 days now...i found a good deal...2007 mazda 6, 1 owner for 58k miles, no accidents or repairs.....for 15000$ out the door price(thats including tax) now he told me that he could give me a 15k loan for the car and i just would pay off the 15k loan that he gave me, with the banks loan for 15k they approved me for....is this a good deal or is this bad? the dealer is hour and half from where i live that is why i wanted to get the loan from him and drive the car home that day...