spend the $25 and actually open an accounting and go through loan application process
you need to get formally approved by pfcu (not pre approval letter) in order to get rate beat from lightstream
here is the tricky part...in order to get final loan application from pfcu...you also need MVPA from tesla...but tesla normally won't send it to you until 2~3 days before delivery date...
so the whole process is something like
get pre approved by both pfcu and lightstream
call tesla everyday to get MVPA with pfcu financing terms (and might need to delay delivery if not enough time)
once get final loan application from pfcu...send loan disclosure page (the one with all the numbers and terms) to lightstream for rate beat (adjust your pre approved amount to match what's on pfcu term sheet)
once lightstream approves rate beat, sign the loan application online and wire the money to your account asap
call tesla to change payment to cash instead of financing
wire money from lightstream to tesla
hopefully timing works out and get unsecured loan at 2.64%