My NRA window sticker (sometimes hard to see because it's on the inside of a tinted rear window) and front plate cover "Life Member:: National Rifle Association" never caused any problems, but when I added a "West End Gun Club" hitch cover and a rear plate cover reading "My other auto is a:: .45 ACP", the two times I've been stopped since have resulted in "Got any guns in the vehicle?"
The first time was by the partner of the Costa Mesa PD Sgt. I spoke with after making a left turn after the red in a construction area (they had blocked several lanes and I ended up across lanes, so thought I should make the turn behind the guy in front of me - the light went red as I made it.) The senior guy basically said, they were really looking for drunks, so don't do it again, goodnight; but his partner (on the passenger side) piped up with the "Got any guns?" To which I replied, no, and if I did they'd be locked up in the utility box - then he says"Mind if we look?" I was a little surprised by the apparent hostility, but said "Sure." He then said "Never mind" and they left.
Much more pleasant (in this respect) was the CHP who nailed me for speeding in a cleverly placed radar trap at the bottom of a long steep grade on one of our toll roads. They had 4 of us pulled over while I was there
but it was fair and square (if sneaky.) After giving me the ticket, he asked if I had any guns. Me: "Yes, locked up unloaded in the utility box." (I was just returning from a match.) He said, okay, have a nice day, and left.
But all in all, I feel it's important in the PRK to let people know we're not all sheeple. I do see probably a half dozen NRA stickers a week here in Orange County, but I really enjoy parking in West Hollywood when I visit my brother so the lefties get a clue