@Ron W. - I'm in California as well. Yes the California Air Resource Board makes modding cars a bit more difficult here as you have to find parts that are C.A.R.B. exempt. These parts will come with a sticker you put on said parts so when it comes time to smog it, they'll see that sticker and know that it's okay and will smog your car as normal. K&N does make a performance air intake for the Thunderbird that is 50 state compliant and C.A.R.B. exempt. I got mine from Amazon and they had a note on the page that said it was carb exempt. So you just want to make sure you get that one and have the mechanic or yourself put those stickers on when it's installed and you'll have no hassle. I've included a screenshot of the Amazon listing for the performance air intake that is legal here in California as well as my air intake with the stickers on it.
forgive my lack of mechanics knowledge but when you say snap off the snorkel does the mean the actual air filter itself? And if altered will it affect it from passing being smoked? and does it improve HP and mileage like the K&N cold air intake? thanks.
Unfortunately for you, it's always California that has stupid laws. According to what i know, your cold air intake will come with a special sticker, that is just for CA inspections. According to the instructions, you do not have to remove the system, this sticker proves it's legit, and actually better than the original.
see pictures of Tbird air filter assy. the snorkel just snaps out or snaps in. No, it will not affect CA smog law.