Stopped Eating while on vacation

Hey folks,

My poor little guy.  He won't eat his food he's been eating for the past two months or his treats.  We are on vacation and I think the 19 hour car ride threw him for a loop.  He does have an appetite though, as I felt sorry for him yesterday and gave him some leftover steak.  Also last night I bought some canned food which he inhaled.  I really need to keep him on his older food diet as he has a sensitive stomach.  Any suggestions for getting him to eat?  We are currently in a very calm situation, but I'm sure it's still nerve-wracking for a 4 month old pooch. If he doesn't eat by tomorrow afternoon I'm going to cut our vacation short and head home.

Thanks
Lee and Feyd