I've been running the Jim Wolf Technology intakes (
Jim Wolf Technology 370Z Dual Pop Chargers Sale! Check it out!) for a little over 10K miles and have had no problems. Dealer told me it would not void warranty. Installed myself (snug fit) but happy with the results. I noticed an immediate improved throttle response (drive by wire is sluggish) and the sound is outstanding. IMO they were a good buy. 30K between service. Here is their website:
Jim Wolf Technology website