Continuity mistake: When Alice and Adam get in the cab outside the bookshop, the number on the back of the taxi is 90167, there are no other markings on the back and the Y on the number plate has a long stalk. When they're pulling away from some traffic lights later, the number has changed to '14290', there are the words "fairaway 95" on the back and the 'Y' has a small stalk. Note that, since the number plate (K651EYW) stays the same, for at least one of the shots they were driving a car around London with the wrong plates on. (00:08:30 - 00:09:25)