I just went through this here in washington state and even though we are abolishing emissions, if you buy a new car out of state (meaning it has less than 7500 miles on it), you have to buy a vehicle that has the CARB sticker under the hood! This number is recorded at the DOL and is the only way you can pay sales tax and therefore, register it for tags.
The Ca vehicle licensing office will also state this on their website under vessel and vehicle registration requirements.
The window sticker (if vin matching) will indeed show its Cal certified— If it doesn’t, pass!
Lastly, all car manufacturers, after late 2000s I believe, adopted strict emissions that allow you to pass emissions and therefore, be used in your state. That said, this does NOT apply to any new vehicle that was allocated to a state that downs not require the carb verified vehicles.
Hope
This helps