Yes you can, as long as its concealed. This falls under the "Castle Doctrine". Your car is considered as a part of your dwelling, so you can definitely carry a loaded handgun in your car. Just make sure it is concealed! This rule was confirmed my my CHL instructor who is a cop and former marine.
"No free man shall ever be debarred the use of arms. The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government"
-- Thomas Jefferson, 1 Thomas Jefferson Papers, 334