This is for the people that keep making treads that don't know how to get the cars ingame.
Your psn or xbox live account must be linked to your social club account. If you bought a SE or CE you can redeem your code in game via the pause menu or via ps3 home screen playstation store. That is if you have a PS3. Im not sure how it work for xbox because i didn't get the game for xbox.
if you go into the garage and stand there for about 30 seconds a message will show up and it will say "Press > to select a special vehicle" when you do this you can pick from 3 cars the Hotknife, Carbon RS, and the Elegy RH8
***Note if you didn't get the Collector's Edition then the Hotknife and the Carbon RS wont show up in the Garage***
For Trevor the Garage name will be "Pillbox Hill Garage" and can be found here
For Franklin the Garage name will be "Grove Street Garage" and can be found here
For Michael the Garage name will be "Vinewood Garage" and can be found here