The Special Key isn't required if one wishes to escape using the Main Door unless he/she receives Tool Positions 2 or 4, in which the Playhouse Key and Padlock Key are in the Special Cabinet, respectively.
However, it is required for all tool positions to escape using the Car.
When dropped, it makes the same noise as the Wrench.
Occasionally, after being thrown, the special key will become stuck. When this happens, you are able to pick it up at any time and it does not make any noise.