[jsbihn]

If the oil is getting on the MAF then someone is way over oiling them. The oil is a topical catching agent and should be going through the fabric of the filter no matter how much vacuum is being pulled.

I have used K&N "charged" type filters in all my performance cars without any issues.
In fact my 600+ hp S/C'ed Vette is running two and my 600 hp S/C'ed M3 Has one... No issues. (and the Vette's LS engine setup is very similar to the LQ setup in our rigs)

Given I have to also say that these are not a set and forget type of setup, just like an oil change for the engine, every so often you want to pull that filter wash it and re-oil it. I think 2-3 sprays of oil should be enough for a large filter.