OP - What @pipeguy is explaining is the best advice you can get in this regard. NFCU and DCU are both excellent credit unions particularly in terms of auto loans. If you have USAA, you should qualify for NFCU, and DCU is easy to join. I belong to both of those, Pentagon Federal CU, as well as a local CU.
I am also a member of USAA as well as Chase Bank and Cap 1 Bank.
USAA is not a credit union , it is a Federal Savings Bank, which is different than any normal bank. It is a savings and loan association federally chartered in the United States. They are chartered and regulated by the Treasury Department's Office of Thrift Supervision. Most other banks are National Banks or Credit Unions.
The CUs beat USAA and the banks on auto loans each time I’ve tried, about 9 times in the past 30 or so years.