Burning oil smell wafting into cabin

[B6_Rakete]

I have a 2004 B6 S4 that seems to possibly have a small oil leak that is causing noxious smells to enter the cabin. I mostly notice this when waiting at a stop light, not so much when underway. The smell is definitely motor oil, not manual transmission fluid, steering fluid, or coolant. If I pop the hood, there is a faint smell of burning oil but I can't tell from where. I crawled under the car and there is no evidence of oil leaks (or leaks of any kind). I tried looking around the heads/back of the motor, but that compact V8 doesn't allow much clearance in the engine bay for inspection. The oil level is at the max and the car doesn't seem to be burning oil otherwise.

Anybody know if:
- The S4 has a PCV valve that could have gone bad?
- There are any oil lines that I should inspect more carefully somewhere?
- If the valve cover gasket/other gaskets are known to leak on these cars?
- There is a air cabin filter that should be trapping this odor?

The car is about to go out of warranty in June and I want to make sure I get the issue fixed before this happens.

Thanks in advance!

[bammercole]

if the car is truly burning oil you should notice a drop in actual oil level, even a small loss would be noticeable after a time. Also I assume you've looked inside of all the plastic panels that are on the bottom of the car, sometimes leaks land on these panels and don't get noticed because they don't land on the ground.