<prompt> Human: Heres the scoop. We both have goodgreat credit. She has 780, I have 810. I cant get a solid answer on whether there is a credit score threshold to get the best rate. Im told rates are between 2.5-3.5. I also cant get an answer as to a threshold for downpayment to lower the rate. Ive seen some mixed reviews as to whether to cosign with most being in the negative in the sense that its potentially a double hit to your debt, but if it could lower my rate by a percentage point could it be worth it?  <response>: Really would make 0 difference with that great credit. Both of you have tier 1 credit. 