Go to Settings > Account > Download History .
Forza DLC often downloads via a specific in-game popup menu rather than the standard Xbox 360 background queue. Do not close the download screen until it completes. 3. Fixing "Corrupted Connection" on USB
Find your Forza 4 car packs and select "Download Again." Choose your USB drive as the destination to keep these files separate from potentially corrupted system cache on the main HDD.
If you have transferred DLC files to a USB and receive a "connection corrupted" error, it is likely a licensing or file path issue.