The K&N filter wont void our warranty it just replaces the stock air filter, and yes that is what the turbonator does. Here are the pics of what im talking about with the intake, first one is with her bone stock from the factory:

,
this is without the first stage, so you can see how much more space you get to suck on vice a 6" by 1" intake:

and finally, here is where i placed the extra hose clamp for the turbonator:

the engine felt more alive without the first stage of the intake in there, plus a little louder at 4,000 RPM. i took a full look at the exhaust, after the main Cat we have a huge muffler, 2 resonators @ the Y connection, then the last 2 mufflers before the exhaust tips, saw no extra O2 sensors, so a cat back system should give us at least 15-20 HP.