Mr. Bean's Holiday

The film opens with Mr. Bean (Rowan Atkinson) driving up to a church, where a fete is taking place. Bean wins the first prize in a raffle - a holiday involving a train journey to Cannes, a video camera, and â¬200.
Following a misunderstanding involving a taxi at the Gare du Nord, a railway station in Paris, Bean is forced to make his way unorthodoxly towards the Gare de Lyon to board his next train towards Cannes. However, a vending machine prevents him from boarding, and he misses his train, giving him an hour to sample French seafood cuisine.
Back on the platform, Bean asks a man, who happens to be Russian movie director Emil Duchevsky (Karel Roden), to use his camcorder to film him walking onto the train. Bean makes a big fuss and keeps asking for retakes, so by the time they are done, the train is about to leave. Although Bean manages to get onto the train, the doors close before Duchevsky can get on. Duchevsky's son, Stepan (Max Baldry) is therefore left on board by himself.
Bean attempts to befriend the boy, who has been told to get off at the next station, and eventually comes to his rescue at the station, unfortunately missing his train again. The train Stepan's father has boarded does not stop at the station, and a mobile number is held up, with the last two digits covered by his fingers. Attempts at calling the number prove fruitless. The next train comes and they board. However, Bean has left his wallet, passport and ticket on the telephone box. Bean and Stepan are thrown off the train.
Attempts at begging and miming to Puccini's "O mio babbino caro" prove successful, and Bean buys the pair a bus ticket to Cannes. Bean managed to lose his, though, and attempts to hitchhike his way there. Mr. Bean soon falls asleep, exhausted from walking and wakes up on what appears to be a quaint French village but is actually a film set for a yoghurt advert. Bean ends up as an extra in the advert, directed by Carson Clay (Willem Dafoe). When Bean's camera battery dies, he recharges it, but accidentally ends up destroying the set in an explosion.
Bean then tries to hitchhike again and a lime-green Mini identical to his picks him up, driven by actress Sabine (Emma de Caunes), who offers him a lift to Cannes. She is an aspiring actress on her way to the 59th Cannes Film Festival, where the film in which she makes her debut as an extra is going to be presented. When they stop at a service station, Bean finds Stepan dancing in a cafe with a band. Sabine agrees to take him with them.
Sabine thinks Stepan is Bean's son, while Stepan thinks Sabine is Bean's fiancÃ©e. On the road again, Bean finds Sabine's cell phone, and Bean and Stepan now attempt to call his father again, but to no avail, and the trio end up driving through the night.
The next morning, they reach Cannes. When Sabine goes into a gas station to change for the premiere, she sees Mr. Bean's photo on TV; he is suspected of kidnapping Stepan while Sabine is Bean's accomplice. However, since she does not want to miss the film in Cannes in just one hour, she does not want to go to the police now to clear the misunderstandings. Therefore, they have to work out a way to get into Cannes without being identified. Stepan dresses up as a girl while Mr. Bean dresses up as Stepan's "grandmother". They manage to get past the police, and Sabine arrives on time.
After sneaking into the premiere, Bean is disappointed to see that Sabine's large role has been cut from the film. He plugs his video camera into the projector, projecting his video diary. The bizarre tale it tells fits director Carson Clay's narration well, and the director, Sabine, and Bean receive standing ovations as Stepan is finally reunited with his father.
After the screening, Bean leaves the building by the back door, and onto the beach, encountering many of the characters from the film. The film then ends with Bean and all the other characters of the film miming a large French musical finale, with arms raised in the air. After the credits, Bean writes "fin" in the sand with his foot. He films it until the sea washes the words away, and the camera's battery dies again.

Question: What does Mr. Bean dress up as to get by the police?
Answer: Stepen's grandmother