wow, does a cop have the right to impound your car for minor mods. You weren't even speeding, hopefully ever thing works out though. Good luck and fill us in on the updates.
The Nitrous system is not CARB legal, the intake element was also not CARB legal, and there could be other concerns, perhaps no catalytic converters, etc.
If a car does not meet all CARB standards, it cannot be operated on California roads, if the car cannot be driven, the officer has a bit of descretion, and apparently decided to impound it. You could have perhaps asked if you could have the autoclub tow it to a repair station, so you could return it to stock, but if the cop were annoyed at something, they would likely impound it anyway.
It sounds like he was annoyed about something, which explains why he went from a front plate, to an engine inspection, to the opening of your airbox, etc. - he went over your car looking for stuff. Perhaps he was having a bad day, perhaps he scraped a street racer off of the road last week, and noticed your wing, and made an assumption, perhaps you were a dick to him, and he went through your car, perhaps he just watched an instructional video on spotting modified cars at the police office.
There are any number of reasons why this happened, but going off of the story, as written, it seems like the cop didn't do anything untoward, its just an unfortunate situation.
Good luck in fixing this situation, out of curiosity, where did this occur?
