What's wrong with having a gun in your car to protect yourself? Frankly, I can't imagine NOT having a gun in one's car especially if someone lives in a place like LA that is so ridden with crime and full of armed car jackings. No one has said the gun itself was acquired illegally; rather, if the story is right, it was that it was in his car and it shouldn't have been.
The problem comes if the state you are in has a law against it, or you are doing it in an illegal manner. Then you need to either obey the law or move to somewhere that doesn't have such laws.
But, the NFL being what it is, is very likely to suspend him for some time. The Rams need to plan on not having him for the remainder of the year. If that happens, my guess is they'll just cut him outright. Depending on what happens in the next few days, they might anyway.