GM KOREA CO. LTD. - Seoul, South Korea

I am a US government employee here in Korea. My Cadillac SRX was shipped here and has substantial damage when it arrived. The transmission, muffler system and about $20K more in parts and labor need to be done. It is still under warranty. Does work maybe done in Korea void my warranty? Is the worked guaranteed under Cadillac? Will Cadillac in the US honor the work done in Korea and continue to cover any problems? Please let me know what the relationship ship is between Cadillac or GM in the US and here in Korea. Want to make sure my car is repaired to US standards and the work guaranteed and will be honored in the US.