Personally on cars this new I wouldn't worry about and go ahead and mod whatever you want. Purchase some nice shelving while your at it for all your stock parts and make sure whatever tune you use is a flash tune that can turn your car back to stock. Personally I'm going to go all out with an upgraded turbo and all supporting mods, then change it back when it's time to smog. 6 years is a long time to not have to worry about it. Don't drive like an idiot and make a wise decision in your exhaust choice and the police should have no reason to pull you over and ask to inspect your vehicle.
Side note and it's probably obvious but suspension and appearance mods are not illegal, same goes for modifying the transmission (clutch, short throw etc.) as well as things like upgraded motor mounts.
Just one more caveat when it comes to exhaust 95decibels is the max but any exhaust that modifys the routing in a significant way can be considered illegal. Think switching. Exiting position or changing from single to dual exhaust or vice versa. The rules are ridiculous but that's what you get when a bunch of people who don't understand anything car related are in charge of trying to keep CA's air clean.
Side note and it's probably obvious but suspension and appearance mods are not illegal, same goes for modifying the transmission (clutch, short throw etc.) as well as things like upgraded motor mounts.
Just one more caveat when it comes to exhaust 95decibels is the max but any exhaust that modifys the routing in a significant way can be considered illegal. Think switching. Exiting position or changing from single to dual exhaust or vice versa. The rules are ridiculous but that's what you get when a bunch of people who don't understand anything car related are in charge of trying to keep CA's air clean.