Use this number after the Brotherhood's storyline to unlock zombie Carlos - 555-5966

£555 3597 - Airport
#819 8415 - Big Willy's Cab
#555 4233 - Bling Bling
#555 3765 - Brown Baggers
#555 2626 - C__cks
#555 4976 - Company of Gyros
#555 2453 - Cycles
#018 0174 - EagleLine Yellow
#911 - Emergency
#555 5966 - Eye for an Eye
#555 3473 - Fire Department
#555 2046 - Foreign Power
#555 4448 - Forgive and Forget
#555 6328 - Freckle B's
#555 4867 - Friendly Fire
#555 7577 - Giftshop
#555 6677 - HazMat
#555 8459 - Image as Designed
#555 3248 - Impression
#555 2662 - Leather and Lace
#555 9467 - Legal Lee's
#555 5926 - On The Rag
#555 2564 - On Thin Ice
#555 7467 - Pimps 'R Us
#555 7973 - Police
#555 3493 - Rim Jobs
#555 8287 - Rusty's Needle
#555 7447 - Ship It
#555 2283 - Spelunkers
#487 6837 - Suicide Hotline
#555 9866 - Tee'N'Ay
#455 8008 - TNA Taxis
#411 - Ultor Security
#4976 - Gyro Daddy (helicopter)
#728237 - Destroy (UFO)
#7266837 - Peewee (mini-bike

Enjoy :)