In addition to the locations in § 173.3(e)(1) (relating to display requirements), flashing or revolving lights may be permanently mounted in a workmanlike manner in fire department vehicles and privately owned vehicles used in answering an emergency call when used by a fire chief, assistant chief and, when a fire company has three or more fire vehicles, a second or third assistant chief, in either of the following locations:
67 Pa. Code § 173a.3