Yeah, I just found one out today acctually and I'm making a video of it.

Step 1: Go to the Turret in the theatre.

Step 2: Spin around three times without stopping and without falling off the ramp.

Step 3: Quickly press Triangle + Start ALOT.

Step 4: While you're doing Step 4 you should get downed by the crawler.

Step 5: Tell your friend to revive you using a knife.

Step 6: Kill yourself with a grenade.

Step 7: Now go to ANY corner.

Step 8: Have your friend revive you again while you press start and Triangle ALOT.

Step 9: Kill the crawler.

Step 10: Don't shoot at the zombies that run towards you.

Step 11: Start gathering a group of zombies for your friend to kill. Keeping running with a horde around the theatre.

Step 12: Hit both traps located on both sides of the theatre. The one in the dressing room and the one next to Juggernog, DO NOT OPEN THE DOOR ON THE RIGHT.

Step 13: You should all have a horde of zombies following you and both traps are on. Watch out for the special surprise.