So I hit 6k and switched to life time HKS filter. No oiling needed. They atually sellling it for the G37 but the intake is the same. I've just got them in. Great price. If you want to stay close to stock. This would be a good option.
My old ones.
The HKS
Got it from
http://amplifiedmotorsport.com/. $59.00 include shipping.
Also switched to Quaker last Friday. They were asking the same for the Mobil 1 and Quaker. I had experience with Mobil but never used Quaker. I wanted to try it.
Peace