Title Says it All...

Need To Have:
Garage/House
Filled up Garage
Car your Going To Dup'

Instructions:
1.) 2 Players 1(With a Car ex: Sultan) 2(That Wants To Dup')
2.) player 2 gets in a Car from the Garage (ex: Gauntlet) Then Takes it out
3.) Player 1 Gets the sultan then Player 2 gets in the sultan and starts up a job...
4.) once in a job take the Car Back To your Garage To Dup and when It says your Garage Is Full And You Need To replace A car, You Replace The Car you took Out (ex: Gauntlet)
5.) Kill Your self to end the job
6.) Once back in the Free roam lobby, the game should have spawned your sultan
7.) get in and take it back to your garage and once again it should say its full then replace a different car (ex:Zion Cabrio)

And There You Go Now you should have Gotten 2 duplicated cars at once xD now sell one and get $$$