I ran a search for this and, except for a very vague reference, I didn't see any posting for this.

For all of you California owners who purchased the Injen cold-air intake for the 1.6L (RD6050), 1.8L (RD6065), or 2.0L (RD6060), Injen has finally received CARB certifications. Remember, without this certification, the intakes are illegal modifications to your engine and you can be ticketed for it (one person in here already has) and you can automatically fail your biannual smog test. To get the CARB number sent to you, follow the directions on this page:

http://www.injen.com/carb.html

For non-California owners, this certification is not necessary, although your state may have different laws regarding engine modifications. Just for reference, CARB stands for the California Air Resources Board.