Probably not a fit with the book theme, but anyway ...
Being flagged down in a supermarket parking lot on Christmas eve to find out your car has a totally flat tire, thinking you've got to ride it home somehow, and then having those total strangers insist on changing it for you just because it's Christmas eve.
Then waiting a week for your only trusted mechanic to reopen from the holidays and fixing the tire at no cost because you had to wait an hour.
Awesomeness!