most of final interview is for the future colleagues - if they like you or not. Your qualification is no doubt - as you have passed the first two round. But can you get alone with people? do they like you? This is important in this trip.
1. be a great listener, not a talker. show insterest to your colleagues' work, achievement, personability, etc. develop some rapport if you can
2. ask for each interviewer's business card at beginning (this is important as you want to know them) and they will talk a lot if you are a good listener
3. talk some about hobbies, families, etc. relax and enjoy.