It is working just ....
... start the game
... go to freeroam
... start the gift redeemer
... install google chrome
... set it as standard browser by starting it
... close chrome
... select a gift plate in gift redeemer
... chrome will run and follow the instructions by clicking continue ( you have to wait 15 to 30 seconds on one screen )
... continue till you reach the nfs world homepage
... look in aftermarket gifts, if the gifts wont appear wait 1 or 2 hours, a day they will appear after some time.
good luck sir