it works for duping but you have to do it as a TIER system.
basically i did it tonight with my accounts i already had setup for birthday glitching.
STEP 1:
create multiple accounts as many as you can on PS3.
STEP 2:
make a backup of your main game with the car you want to dupe.
STEP 3:
load main game save and send the car you wish to dupe to you first PS3 account (user 1)
STEP 4: exit main game, delete save, backup original. (so on your main, its as if you havn't gifted a car at all)
STEP 5: go onto user 1, load game, accept gift.
STEP 6: exit game, backup save, overwriting the previous.
STEP 7, same as STEP 3-5 but you just go down the list of users.
basically this way once you reach the end of your list of accounts, each one will be sitting there with a save you can load up into and each one will have the car you wanted to dupe.
since you can't transfer back in the same day, comeback the next day, load up all the dupe accounts and send the car BACK to your main.
there you have it, tons of duped cars.
works for paint chips, and anything else as well.
tedius and boring, but effecient.
now to find out what the most expensive car is to sell in the game lol.
