Beside that i am sure they are not supportive and don't make it easy for people to import vehicles from abroad, specially the models they sell there too.

I imported a bike temporary on a 'carne de passage' once.

Registration on your name needs a address confirmation by your embassy which i can get only if i am registred with the embassy living there, or if you got a property on your name which reguires the yellow book which you only can get if you have a minimum 6 month visa either work permit, residence visa (non-immigrant) or retirement visa.

I had one of the visas when i bought my two bikes (and condo) and was still registred at the embassy, but i am no longer and can't register a vehicle on my name anymore. This is recent first hand experience.

How about getting her an ATM card and deposit it until you pass

Bangkok Bank is the worst check peoples review in here, i got an account there, and did you try the main branch? SCB and Kasikorn my preference.