Auto loan primary good credit joint bad, advice

[Anonymous]

I was in the market for a used auto loan but will not qualify for a good rate due to my credit history. I am a recent grad made some mistakes during school but to fast forward my mother will sign to be the primary on a loan on I will be on as a joint. Will the rate base off her credit score or mine, she has fairly good credit. Another issue that we have my mother is apart of the home affordable program where she refinanced the house years back. Will this be a problem? Will they try to put her on her previous mortgage payment? 

thanks for advice!

[dharalex]

I don't know anything about the home affordable program, but from experience, I know that they will take the one with the best credit to figure rates. Years ago, my credit wAs abysmal. My dh is a stay at home dad. So I had the income and he had the great credit. So like pb&j, they used his credit and my income, and voila...we bought a car!