yea, I wouldn't worry to much, you said he sounded like he had something in his throat. Sounds like maybe this was a reverse sneeze. Which is normal for this breed. I do recommend you looking up the breed online and researching the breed carefully if you haven't done so.
There is alot of helpful info out there. This may also make you feel better.
My boy loves the car, I take him everywhere. And I did when he was a little one. When i first started taking him out he would get car sick, but once they are in the car for a little while this will subside and they will get used to it. I know that most Yorkies love going on car rides.
