Upon release, the code "UNLOCKALLTHINGS" used to work to pop this achievement. They've since patched it out. If you want to use this code to get the achievement after you've recieved the patch, here's what you'll need to do.
1) Delete your savegame by going to System Settings > Memory > Your storage device. If you want to copy it to an external drive so you can restore it later, that's fine. Also delete any DLC for the game.
2) Remove the patch by going to System settings > Memory > Press Y over your hard drive for device options > Clear system cache. It will confirm that you want to perform maintenance, say yes.
3) Run the game, and when it prompts you to patch it, decline. You'll be offline for the rest.
4) Create a new profile, and enter the code "UNLOCKALLTHINGS"
5) Enter a career race day and leave, and this achievement will pop, along with a few others if you don't have them already.