Got stopped by a Ride program on my way back from a Picton game once with others in the car, I know we weren't the only car full of airsofters that got stopped either. After the officer saw that I hadn't been drinking he took a closer look at us (still in our BDU pants but no kit on) and asked if we were in the military. Just told him we were leaving from an all-day game at the nearby paintball field and off we went. No ask/mention of guns, airsoft, paintball or real.
I generally try and stick gun cases in the trunk. Out of sight, out of mind. If I was ever asked if there was anything they needed to know about in the car I wouldn't have a problem telling them.