(gun won't fire if no mag in) - that's the first thing I take care of..
So I put a round in the chamber - how? by stripping it off the mag or dropping it in with your fingers?
how do i unload the thing completely when i get home - assuming you have a ccw since you're driving with a loaded pistol.
anyway, lock the slide back and put in your mag and let the slide go forward then drop the mag and rack the slide. (safety off or on) that should eject the round. if you don't let the slide work as designed the ejector pin won't be over the rim of the shell.