I want to finance a 2011 mustang, I'm 19 and the dealer I went to said either you get a co-signer or it's $4k down, I have no co-signer but I do have $4k to put down, my sales person said if I do it, it's gonna be around 300-350 a month with interest. That's cool I can afford that but how does insurance work? I understand or at least I heard when finance a ...