I have received my DDIN kit with the optional Left Side Buttons, but I could not find any software drivers in the package. There are 4 USB cables and the LCD panel itself, so I suspect I will need drivers for at least the HDMI Screen 800x480, the SD Card Driver, and the USB Button Interfaces.
I did not see the driver links posted on the ebay listing page either, so I hope Derrick can post a download link with all the latest drivers available.
Meanwhile I started a worklog for my project here:
2012 Camaro In Dash PC Project