One of the documents required in the vehicle registration/transfer process is a residency certificate (or yellow book/work permit/etcetc).
how would the car get registered in another province without proof of address ?
I purchased a BKK plated vehicle, DLT in BKK removed previous owner name and added mine how ever that is only part of the transfer, that had to be completed in my home province which involved more paperwork and signatures..... took days but finally book was returned with new number plates.
All in all a very annoying time consuming process and in future I will not buy a vehicle from a different province unless a substantial discount is negotiated.