Intellivision Lock 'N' Chase tunnel trick
Just before entering the side tunnel move the joystick (or Disc) up and down rapidly and Lupin will be moving vertically on the side of the maze and your points will increase.
The only way the get out of it is to get kill ... as far as I know.
Also, notice that the exit doors are opened even if there is still some dots to collect but I can get out ... even after picking up the missing items.