Hey there !
I just tell the LEO when they approach the vehicle first thing, that I have a firearm in a holster on my side, and ask how they would like to handle the situation. 100% of the time I was commended for being so up front and honest about it. They were very cool about it.
PS. 98% of the time I got off with a warning!!!!
For all of your other questions, my answer would be " Get a CCW permit and all bases are covered." It is like taking out an insurance policy for the gun laws.