Taxi - Tuxedo (Book 6)
When Carmen unexpectedly receives tickets for the opera, she tries to persuade Ulrike to accompany her.
Ulrike doesn't fancy operas. When her excuse doesn't seem to work she finally agrees to go, but only under one condition, which she believes Carmen will never agree to - that she may wear a tuxedo.
Taxi - Tuxedo is the 6th book in the Taxi series.