Forza Horizon 3 DLC no longer available for download following Forza Horizon 5 DLC...

Hey there -

Unfortunately, Forza Horizon is no longer available for sale by design. From
Turn 10 Studios:

On October 20, the original Forza Horizon for Xbox 360 will reach “End of Life” status. That means that the game and its associated DLC will no longer be available for purchase. Players who own Forza Horizon before that date will still be able to
download and play the game and its associated content as normal. After that date, however, Forza Horizon and its associated DLC will no longer be for sale.

Sorry for any disappointment this may cause.

Hi SquallLion1

Unfortunately Forza Horizon 2 - Storm Island has reached "end of life" status and was removed from Xbox store on September 30th 2018

Here is an extract form the Forza Week in Review post on https://www.forzamotorsport.net

"Forza Horizon 2

A heads up for the Forza community: Forza Horizon 2 will reach “end of life” status on September 30. That means that the game and its associated DLC will no longer be available for purchase. After September 30, players who own Forza Horizon 2 will still
able to download and play the game and its associated content as normal. However, Forza Horizon 2 and its DLC will no longer be for sale. Forza Horizon 2 is currently available as part of August Games With Gold so, if you haven’t played it already, now is
a great time to grab it."

The DLC for Forza Horizon 1 and 2 is no longer available for purchase, if you can find a code that hasn't been used, you should be able to redeem it to get the DLC

Welp, the forza horizon 3 reached his end of life so it may be impossible to install the dlc's. But you can still use thelost77's answer so maybe that will work.

My order # for the expansion pass from 12/07/2016 is 27c2c727-3c82-4c8a-8b22-1646b68fdb8d