Novos carros chegam em janeiro.

hi i am new here in this forum. I wnt to know one thing. I late an flashed xbox360 with lt3.0 and the lastest dashboard. I am banned from live but i want to know if exists any way to install the dlc pack with new cars for forza motorsport 4. i ve download some packs ive tried to install them for usb but i cant do it with sucecc. Thanks