Found this today, floating in mid air tank 

I am not moving at the time of screenshot i am just sat there ,

how to do it is easy , just cross the tracks at K2 and destroy the round looking object in front of you by ramming it , back up and mount it as its still there but not visible

when spotted just back up a few meters and let them shoot at your lower frontal armor, they cant see there is an invisible object in front of you and your protected,

nearly all tanks will shoot lower front if at distance and not go for your turret ,this gives you plenty of time to bang them back.

I made a video to clarify where this is ,tank in video is now powerfull enough to mount but sits behind ok note when i fire aiming forward rounds bounce but am able to fire over the top