Au Revoir, Crazy European Chick, by Joe Schreiber

Fast paced and outlandish but funny and enjoyable YA. Like Carl Hiaasen or such. Perry is reluctant to take his family's visiting Latvian exchange student, Gobija, to the prom, but when she whirls him into NYC for a series of assassinations, he finds there was more to her than he thought. Going to be a movie, and I bet it will be a fun one.