Seems like this is an RS4 with a rally conversion. That's why you have bigger shocks, and the tires look like they're for offroad use.
I think the reason you need so much air is because you don't have an air filter...
For the battery pack, if you can't find a way to open it, it's time for replacement. Might I suggest carbon fiber upper deck?

P.S. Do you plan on keeping it rally?