This slip up occurs in the episode where Mr. Bean is having a picnic (the one where he fixes the kid's boat, and ends up controlling an old woman's wheel chair). When a thief gets into the front seat to steal Mr. Bean's car, the steering wheel has disappeared. We find out it is because Mr. Bean has packed the steering wheel in his lunch suit case.

However, when Mr. Bean exits the car before the thief arrives, the steering wheel can still be seen through the windscreen as Mr. Bean walks away, so he never actually removed the steering wheel from the front seat!