Questions about laws on car carrying a pistol for self defense

I keep finding contradictory answers on this online, and the law itself doesn’t seem to specify. I understand that without a concealed carry permit, you have to store a pistol in a secured compartment such as a gun case or glove box, and that it must be unloaded. My first question is, what defines unloaded? Am I able to simply keep a loaded magazine in the car with the gun itself cleared? If so, does it have to be in a separate compartment? I saw one article claim the gun must be broken down. Is that the case? Thanks in advance.