That is a decent APR for a new ride like the 370z. Is that 60mos? My dad works for US Bank so I'm eligible for a 4.5% due to his -.5% employee credit. But anything under 5.5 is very decent for 60mos. For 48mos, look for no more than 5%, I think prime is around 3ish (
Prime Rate | Federal Funds Rates Discount Rate Fed Fund Reserve Lending COFI), so banks would be making at least that 1% on top of it. Don't expect anything lower unless you go under that 48mos period.