What does the tooltip mean for the Travelers Tundra Mammoth where it says it carries vendors?
It means just that! It comes with two vendors. One sells reagents (including poisons) and the other sell trade supplies, like thread and parchment. The trade supplies vendor also sells some statless fashion clothing. If you’re not using the vendors and want to let your buddies hop on, there will be an Eject button to throw the vendors off and make room for your friends. And yes, only people in your party or raid can get on your vehicles. No random strangers will be jumping on your mammoth or motorcycle.