This varies greatly on the lender...most of the captive lenders advertise their "specials" so I will that different lenders have different standards. Mercedes-Benz finance for example have somewhat leninent standards as 680 will get your their best advertised rate along with someone with a score in the 700s. Toyota on the other hand will give someone in the 650 range their best advertised rate.
This even goes deeper if you have history with the lender. If you perfectly paid them in the past and came back with scores in the low 600s, the F&L could sometimes convince the lender to give that person the best rate. It all depends... the general rule is that high volume makes tend to be more lenient on scores versus lower volume.. i.e. Porsche's best rate doesnt start until 720... no ands ifs or buts.