appinfo.dat is just a file that gets updated with the latest list of supported applications from Pioneer's servers. It is used to populate the recommended app list. You aren't going to be able to run the AppRadio app in the background by just changing settings files. It has to be a change to the code of the application (via a MobileSubstrate plugin).
Edit: I may be able to work with the UIBackgroundModes continuous setting. Need to look into that some more.
Great!!! Mike is back with another beta, what's new on this one Mike?, I hope the UIBackgoundmodes helps you somehow find a solution for this backgrounding issue, you mentioned that we would need to make changes to the code of the aplication via MobileSubstrate plugin, I would be more than happy to take a look inside the application if you just give me an idea how to access the code with mobilesubstrate.
Just some more clarification:
Every supported app needs to include the Pioneer API that communicates with the head unit. When the application launches, the API registers the application with the head unit and allows it to display on the screen. When an application resigns to the background (or closes), the API tells the head unit to disconnect for that application. Backgrounder worked by telling the application to skip the code that gets executed when the app is closing, allowing it to maintain a connection to the head unit while it was in the background on the phone.
If someone wants to take a stab at writing a port of Backgrounder for iOS 6, I can point them in the general direction. Other than that, the only way I see getting this working is if we gain access to the Pioneer API.
Also please point me in the general direction to take a look at backgrounder code and see if i can fix it somehow, I know someone did it before so it wouldn't hurt to try, i will be waiting for your instructions, thanks...