By calculating the remaining parking distance at the front and back the acoustic peep tones of the Volkswagen Transporter ParkPilot assist the driver whilst reversing. The closer the vehicle comes to an obstruction, the greater the frequency of the signal tone becomes, until a continuous tone is emitted. These peep tones also serve an alternative function. By “bleeping” out the curses and swear words of an enraged boss on the front passenger seat, in exactly the same way they are used to censor x-rated words in an interview for instance.