While in Thailand, I never once heard someone pronounce it as "pod", always Pad Thai

In my experience I never hear the 'D'. It's like it's dropped and you are left with "Pa Thai". Maybe it's because the letters sound the same and the flow of speak takes it away.

Either, really. And you’ll hear Thai people pronounce it either way (depending on their English reference - usually British), since locals will not call it “Pad Thai”.

Not sure what you mean by this. This is the name in Thai and "ผัดไทย" ([pʰàt tʰāj] in IPA) is what is written on shops and carts where it's sold.

The vowel in "pad" is in between the two options given in the question above. Unlike English, where accents primarily change the vowels, vowels stay quite constant across accents in Thai.

The /a/ in Thai is a central vowel. This is different than English /a/, which is a front vowel. And /o/ is the open back vowel. That is why it falls between English ⟨pad⟩ and ⟨pod⟩. And if you don't speak a language with such a vowel, any particular utterance will probably be mentally mapped to one or the other.

I mean that I’ve heard either pronunciation. And when addressing to English native speakers, the pronunciation may not be connected to local custom...

The Google Translate audio is exactly how I've heard it being spoken by Thai people: https://translate.google.com/#view=home&op=translate&sl=th&t...

I've always heard "pád", but I've never been to Thailand or heard it from them.

Almost rhymes with "mud". Like "Pahd" but even more "uh".