EASTER EGG:
The "Easter Egg" is mighty simple since I am just a wee mapping noob.

-To escape the map you most open 3 doors to an airplane (which is awaiting you in a hangar)
-The hangar is located near power (go through the warehouse and follow the red arrows on the floor)
1.) The first hangar door is unlocked through activating power
2.) The second is through shooting five bears around the map:
- BEAR #1: located next to the trip mines in one of the "Brick House's" sheds.
- BEAR #2: located behind a desk in the Dealership
- BEAR #3: located on a shelf in the grocery store (look low)
- BEAR #4: located in a zombie barricade window in the mansion with the fountain
- BEAR #5: located in the warehouse (look high)
3.) The third door is unlocked through purchasing the endgame (30,000)

SONG:
(If anyone is curious its - "Turbo Killer" by Carpenter Brut)

In order to activate you must damage three skulls around the map:
-SKULL #1: located ontop of Quick Revive
-SKULL #2: located on the second story of the "Brick House"
-SKULL #3: located outside the hangar near a cargo truck (look ontop of crates)

ROCKET SHIELD PARTS:
Window Part: An alley near the mechanic shop (where box first spawns)
Gas Tank: Upstairs bathroom of the mansion
Eagle Base Part: Ground level of the warehouse