Technically speaking, any modification will void your warranty. Basically if anything goes wrong with your car and the dealership denies you warranty coverage, if you take them to court they will do whatever they can to trace the issue back to your aftermarket item. A cold air intake, even if it is a nismo one, if it is installed by you, still technically voids your warranty. If you get a nismo intake and it is installed by the dealer (who WILL charge you way too much) then your warranty will still be intact, since it was installed by Nissan technicians. However, people sometimes do get around such problems by replacing their stock intake when they go in for warrnty service. Just be really really careful.