Welcome to YT
How is your little guy today?
Wow - he has done a lot of traveling in his short time with you. The good thing is you know he doesn't get car sick. The panting is usually a sign of anxiety & when my Roxy does it on a car trip - that's her way of saying she needs to potty.
You might find some helpful info here in this link as a new yorkie owner
http://www.yorkietalk.com/forums/gen...w-parents.html