Most states have laws protecting gun owners from prosecution when carrying firearms in their vehicles, and federal laws while they may declare post office property as "gun free" zones, in a state like Florida, good luck finding a jury willing to convict someone of felony possession of a firearm in a prohibited location for leaving their licensed firearm in their car while they went into the damn post office.
My philosophy is this: If you're concealing properly, no one will ever know. I carry any and everywhere, military installations being the one place I'm still very hesitant to take a firearm.
