On a game on the map Bridge, the game started out with 3 players on my team, and 0 on the other. Playing a Proxy, I go to defend the EV to get some early XP, and I was trying to figure a way onto the EV itself. I did and I found a way to stay on (as it tried to slope me off). I then tried planting a mine and it disappeared, but still gave me the mine back and the XP for planting it. Repeating this over and over again gave me up to 4k exp in the beginning of the game within at least 2 mins.