Ok...after getting a lot of refusals and denials from almost all of Tesla Service centres for overseas SIM card replacement into my brand new P3D with FSD3.0, 1 Tesla service centre has finally agreed to replace my LTE SIM card from overseas with AT&T one which comes with my car. They had no idea at first and kept my car for almost 2 weeks for taking down all the trims and dismantling my FSD computer piece by piece(according to them)it’s not easy as model S and X and old model 3 computers. After installing my overseas SIM card and changing internet configurations like APN,....etc, they told me to come pick it up before shipping it to my home country, Myanmar, which is also one of the grey markets, unexpectedly.... everything works including data internet while it was still in United States. I told them it shouldn’t be working in United States as it’s not post paid SIM card and the credit I have inside my pre paid overseas SIM card is not enough for 2 MB of data while in roaming mode. They reset my Tesla and it’s still working even after that reset. Technicians from Tesla service centre have no idea why data internet is still working with overseas SIM card in it. If you guys know or have some ideas why that one is working, please let me know.