Reading this book requires suspension of belief and at first I wasn't willing to do that because my mood has been like that lately and then I got into the spirit of things. Yes, it is very implausible that the hero thinks our sheltered thirty four year old heroine is involved in a theft ring by a mob boss and he not only saves her, then actually kind of forces her to accompany him to Mexico City.
And I did find him heavy handed at first, getting her a make-over but then his concious kicks in and despite his jaded behaviour he realizes that she is not involved but he needs her to go with him and after some prodding she gets into the spirit of things, the whole adventure bit since it is something that she hasn't done before. The hero on his part finds himself totally confunded by her, her innocence shouldn't attract him but it does.
If you look past the whole unbelievability of it, like how they are captured and about to escape and the hero goes back for an artifact or the fact that he actually puts the heroine in mortal danger with his whole charade, you kind of enjoy the book.