Like others have stated, it could cost you a whole lot of money in THIS state to keep that right under the FOPA. Take a look at what NRA-ILA says:
FEDERAL LAW ON TRANSPORTATION OF FIREARMS
A provision of the federal law known as the Firearms Owners’ Protection Act, or FOPA, protects those who are transporting firearms for lawful purposes from local restrictions which would otherwise prohibit passage.
Under FOPA, notwithstanding any state or local law, a person is entitled to transport a firearm from any place where he or she may lawfully possess such firearm to any other place where he or she may lawfully possess it, if the firearm is unloaded and locked out of reach. In vehicles without a trunk, the unloaded firearm shall be in a locked container other than the glove compartment or console. Ammunition that is either locked out of reach in the trunk or in a locked container other than the glove compartment or console is also covered. FOPA also seems to provide for necessary stops, like gasoline and rest.
Travelers should be aware that some state and local governments treat this federal provision as an “affirmative defense” that may only be raised after an arrest.
http://www.nraila.org/gunlaws/federal/read.aspx?id=59
Just ask Phillip Dominguez how much exercising his 2A rights cost him after being arrested at LAX for lawfully possessed guns. I believe his case has been dropped since then, couldn't find an update. But I doubt very much he will get any of his legal fees back. Not sure if he got his weapons back either. California is NOT a gun friendly state. As I said before, take the scenic route. Why bother with the potential problems that a zealous LEO could make for you here.
http://www.msnbc.msn.com/id/28589280/
Sensibly Progressive has update. I blogged about his case a few days ago -- Mr. Dominguez is a law-abiding construction company owner, who owned a registered "assault rifle," which in California he could legally take from his house to a shooting range. He was going shooting with a friend who was arriving by plane, and was arrested at the airport on the apparently claim that by stopping at the airport in the middle of that drive he broke the law.
The update notes that they followed with a SWAT raid on his house and seizure of all his (legal) firearms, and those of his family.
Fortunately, he's got some first rate firearm attorneys. If you'd like to contribute to his defense, click here.
http://armsandthelaw.com/archives/2009/02/update_on_phill.php
Here, did a bit of digging, he plead no contest to a misdemeanor weapons charge and THEN the felony charges were dropped.
http://www.nbclosangeles.com/news/local-beat/Loaded-Gun-Plus-LAX-Equals-Bad-Idea.html