Tanks have no sound and dont appear on map

During multiple games of RedSec, you find yourself getting killed from a tank that either runs you over or shoots you in the back from a very close range.  There is no audio indicating that a large vehicle is coming or doesn't even appear on the mini map or the main map.  You can hear the Glider, Helicopter and ATV from the other side of the map but not a tank.  Something needs to be done about the Tank audio or the player base is going to plummet.