I was in the large tank, the M1 Abrams or possibly it's counterpart. Twice an engineer destroyed my tank with a half a clip or so to my rear from his sub machinegun. I was in third person view and I saw him run right up behind me and shoot the back of my tank, I couldn't quite see where. Blew me up. Then in killcam I saw him reloading his SMG. I chalked it up to imagination until the exact same thing happened again when I went back next spawn. Same guy.
Where is this magical spot on the tank where it can be blown up by a simple sub machinegun?