2012 Leaf SL
I had a problem when driving my Leaf, where after braking and then accelerating again there would be a very noticeable clunk, thunk (or thump) from underneath the car. I found play in the CV joints so I replaced both of them, which made the clunk even louder. The clunk only happened when accelerating and is no worse in turns.
Ultimately I found the REAR MOTOR MOUNT was quite deteriorated, the rubber split in two places. Replacing the motor mount totally solved the clunk. It also fixed a pulsating braking problem, as the motor was probably twisting, causing it to fight the brakes (which still have their original pads).