How about we commemorate our meeting with other Grenadiers by sticking small "A" chevron decals on the bottom of our left rearmost driver side glass for LHD or right side glass for RHD, much the same way fighter pilots display their "kills" below their canopies? We would display up to five chevrons. When you meet a sixth Grenadier, your five come off and a new agreed-upon color is substituted. That way, no more than five chevrons are displayed at a time. What do you think?