here's what I did to 1.24% with DCU, 65 months.
Applied loan first. upon approval, moved forward with becoming a member. Loan application was made on 6/9, check is being delivered to me 6/12. They give you 90 days to setup the direct deposits etc, which if you fail to do the rate jumps back to 1.75%, I didn't do the Tesla Match route since delivery is supposedly a week away and I didn't want to change any paperwork. Plus their checking interest rate 0.5% helps, if I maintain my usual balance then over a 5 yr period DCU will have actually paid me more in interest than what I will pay them on the loan, LOL...