[edwin907]

I'm pleased with my F-Sport intake as well. There does seem to be an improvement in throtte responce. Or maybe my stock filter was that dirty, no, the engine does "snap" at little more at the higher rpms, and to me seems a bit better at lower ones.
You know to always check here before modding your car. This forum is absolutely invaluable and has saved me hundreds of dollars and a lot of worry. Look at it this way, the "dealer" owes you one now, get them to turn off the DRLs or something at your next checkup. Get your filters there and drop in with your beautiful IS just to check new cars out every now and then.
The guys at my local Lexus dealer love to see my IS 'cause it's not totally stock. I just finished the JIC coilovers/F-Sport sways and I'm going to take if for another spin and I think I'll go by there and pick up an oil filter. Of course only 4K to go on my Mobil oil, but I'll get a filter now just for the heck of it.