The Proton Pack in the Realistic version of Ghostbusters: The Video Game has a set of blinking lights on the left side of the Blue Chaser Lights. These lights were inspired by Ray's (Dan Aykroyd) Proton Pack from the first Ghostbusters Film.

These lights aren't actually on the Proton Pack, but are a result of the paint on the Proton Pack's shell being chipped away and the adjacent lights shining through. The lights were still added to the game's Proton Pack anyway.
Contributed by Pogue-Mahone