I called EA support on the phone, and they are looking into fixing this problem. The problem is what I suspected, Shift 2 Unleashed and other Origin games use a "unlock" system for "DLC" instead of actually downloading DLC. For these games, the EA server should be sending "unlock" messages during game login for any "DLC" content the user has purchased or otherwise received on their Origin account for games like Shift 2 Unleashed that use the "unlock" method. The problem is that EA servers are no longer sending these "unlock" messages at game login. EA is now working on fixing this problem. I assume I'll get an email if and when this problem gets fixed.
I tried this again and it's still not working. If I start with no save, or one of the saves I made before I logged in, the Limited Edition content is not unlocked, this includes 3 cars: Lamborghini LP640, Alpha Romeo Giulietta, NIsan Silvia, and 3 events: manufacture showdown, old versus new, single type. I asked for EA support to call back and when they did, they claimed that they don't offer support for old games like Shift 2 Unleashed, even though Origin and Steam are still selling it. I tried chat the next day and at least they claimed they would report this problem to others on the support team.
Note that the SpeedHunters DLC is handled differently, and since it was changed to a free download for the old EA version, before the Origin version was released, so any Origin version will include the SpeedHunters DLC. I think career mode starts off with 3 of the SpeedHunters cars, and more are added as you level up. This information is in one of the xml files, and you could edit that xml file to unlock all SpeedHunters cars at the start of career. However, enabling the Limited Edition content is handled differently and normally requires that when you log in from the game, that the Origin server send the messages to the game that you have the Limited Edition version, and when you first log in, you should see multiple pop up windows showing the cars and events that are unlocked for having Limited Edition.
The Silvia is nice, but the main car you want from Limited Edition is the LP640, which is the fastest car for circuit and 1/4 mile drag.
Similar to you, I have the Limited Edition content in a set of saves, but I can't login due to the password issue, and I can't restart career mode with the Limited Edition content.
Yet another way this problem shows up. A friend of mine had a hard drive crash a while back and is in the process of reinstalling everything on a new hard drive. He has the EA DVD version of Shift 2 Unleashed Limited Edition. When installing from the DVD, before it actually starts the installation, it prompts for an activation code to be entered. The EA Store download version of Shift 2 also uses an activation code, but I don't recall if it required the player to manually enter the code or if the code was automatically entered. Both versions have a de-authentication and re-authentication process. If uninstalling Shift 2, the first step is to do a de-authentication so that Shift 2 can be installed on another system. I seem to recall a limit of 5 authentication cycles, perhaps based on the time between cycles (if enough time has passed, then the count may get reset back to 5).
Other than a different sequence for authentication, it seems that EA DVD and EA Store download versions are the same, and now both versions are no longer able to unlock the Limited Edition content unless a player backed up a save with the Limited Edition content. I also have a Dr Pepper Camaro from a promotion, and it also no longer gets unlocked, but I have backups of saves with the Camaro and Limited Edition content.
I have now tried uninstalling Shift 2 and Origin, cleaning and/or deleting related folders, then doing a download and install of Origin, followed by an Origin download and install of Shift 2 Unleashed Limited Edition, which I have on my Origin account. This did not fix the issue with the missing Limited Edition content, nor did it fix the issue with the missing Dr Pepper Camaro. Worse, the Origin version crashes without explanation on the prologue 2 lap practice run, making it unplayable, but this is because the Origin version needs nvidia/geforce physx installed, even if you don't have an nvidia/geforce video card. Downloading and installing physx fixed the game crash, but I'm still stuck with the missing Limited Edition content (3 cars, 3 events), and the Dr Pepper Camaro.
I reported this to EA support again (last time was back in June 2018). I don't know if anyone from EA reads the stuff here at Answers HQ and reports this stuff back the studio people that might be able to fix these problems.
What I don't understand is that the origin version of Shift 2 is significantly different, (size is 11MB versus EA size of 23MB), with what appears to be significantly enough changes that EA could have just defaulted to including all special content like Limited Edition, promotional stuff (like Dr Pepper Camaro), and loyalty stuff as part of the Limited Edition or just including this stuff in the standard edition, since it's an old and cheap ($20) game.
