the Saigon consulate requires an appointment and you must bring the email that you receive, confirming the appointment. They will not let you in without it.
Also, the requirement for bank statements is confusing. They want to see 6 months of statements.
Finally, the US$40 must be in crisp, brand new bills.
that may be the law but in 8 years here, I’ve never been asked by the police to show my passport. Just my DL. But if one is only a tourist, without a DL, then yes, they would need to show it.
As it’s been said many times, the requirements depend on the office. I moved the required funds to Thailand and applied to change my tourist visa to Non-O for retirement at the Chiang Mai office merely days later. The application was accepted and I was told to go back at the end of the month to get the stamp.