Manufacturers always say that they have "applied" for the CARB exempt status, but most never get it. It depends on how much the intake is needed to warrant the actual cost to get it done and since people still buy the product w/o the status, it even less on their minds to get it. The 2.0 Injen intake has been on the "applied" list since it came out, about 4+ years ago and Injen is the leading manufacturer for CARB exempt intakes(it's what made them so explosively popular when they first came out).
And unless you're running a giant loud exhaust, running around with an intake shouldn't give you a problem. So long as you're not causing any trouble or sticking out from the crowd(street racing, needlessly revving your engine, underglow kit, body kit) you wont get busted.
Oh and to answer your original question, no, there are no CARB exempt intakes for the N/A Mazda3 available.