First go used for a year or two with a less expensive car. Save the difference per month, get your score over 740 and you will have the M.
I just got my loan from Pen Fed. They are funny. First I applied for the loan saver, its a loan with a balloon so you have a lower payment, because I was going to buy a 45k car. I never finished the application and the dealer would not deal so I walked.
I then bought a less expensive BMW (37k) on a straight loan through Pen Fed and got approved. I called them up and told them to cancel the first loan which they did online. Today I get home and there is a 46k check from Pen Fed in the mail. Now have to send it back...